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<section id="module-csv">
<span id="csv-csv-file-reading-and-writing"></span><h1><code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> --- CSV File Reading and Writing<a class="headerlink" href="#module-csv" title="Link to this heading">¶</a></h1>
<p><strong>Source code:</strong> <a class="extlink-source reference external" href="https://github.com/python/cpython/tree/3.14/Lib/csv.py">Lib/csv.py</a></p>
<hr class="docutils" id="index-0" />
<p>The so-called CSV (Comma Separated Values) format is the most common import and
export format for spreadsheets and databases. CSV format was used for many
years prior to attempts to describe the format in a standardized way in
<span class="target" id="index-1"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc4180.html"><strong>RFC 4180</strong></a>. The lack of a well-defined standard means that subtle differences
often exist in the data produced and consumed by different applications. These
differences can make it annoying to process CSV files from multiple sources.
Still, while the delimiters and quoting characters vary, the overall format is
similar enough that it is possible to write a single module which can
efficiently manipulate such data, hiding the details of reading and writing the
data from the programmer.</p>
<p>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> module implements classes to read and write tabular data in CSV
format. It allows programmers to say, "write this data in the format preferred
by Excel," or "read data from this file which was generated by Excel," without
knowing the precise details of the CSV format used by Excel. Programmers can
also describe the CSV formats understood by other applications or define their
own special-purpose CSV formats.</p>
<p>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> module's <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> and <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects read and
write sequences. Programmers can also read and write data in dictionary form
using the <a class="reference internal" href="#csv.DictReader" title="csv.DictReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">DictReader</span></code></a> and <a class="reference internal" href="#csv.DictWriter" title="csv.DictWriter"><code class="xref py py-class docutils literal notranslate"><span class="pre">DictWriter</span></code></a> classes.</p>
<div class="admonition seealso">
<p class="admonition-title">همچنین ملاحظه نمائید</p>
<dl class="simple">
<dt><span class="target" id="index-2"></span><a class="pep reference external" href="https://peps.python.org/pep-0305/"><strong>PEP 305</strong></a> - CSV File API</dt><dd><p>The Python Enhancement Proposal which proposed this addition to Python.</p>
</dd>
</dl>
</div>
<section id="module-contents">
<span id="csv-contents"></span><h2>Module Contents<a class="headerlink" href="#module-contents" title="Link to this heading">¶</a></h2>
<p>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> module defines the following functions:</p>
<dl class="py function" id="index-3">
<dt class="sig sig-object py" id="csv.reader">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">reader</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">csvfile</span></span></em>, <em class="sig-param"><span class="positional-only-separator o"><abbr title="Positional-only parameter separator (PEP 570)"><span class="pre">/</span></abbr></span></em>, <em class="sig-param"><span class="n"><span class="pre">dialect</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'excel'</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">fmtparams</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.reader" title="Link to this definition">¶</a></dt>
<dd><p>Return a <a class="reference internal" href="#reader-objects"><span class="std std-ref">reader object</span></a> that will process
lines from the given <em>csvfile</em>. A csvfile must be an iterable of
strings, each in the reader's defined csv format.
A csvfile is most commonly a file-like object or list.
If <em>csvfile</em> is a file object,
it should be opened with <code class="docutils literal notranslate"><span class="pre">newline=''</span></code>. <a class="footnote-reference brackets" href="#id4" id="id1" role="doc-noteref"><span class="fn-bracket">[</span>1<span class="fn-bracket">]</span></a> An optional
<em>dialect</em> parameter can be given which is used to define a set of parameters
specific to a particular CSV dialect. It may be an instance of a subclass of
the <a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a> class or one of the strings returned by the
<a class="reference internal" href="#csv.list_dialects" title="csv.list_dialects"><code class="xref py py-func docutils literal notranslate"><span class="pre">list_dialects()</span></code></a> function. The other optional <em>fmtparams</em> keyword arguments
can be given to override individual formatting parameters in the current
dialect. For full details about the dialect and formatting parameters, see
section <a class="reference internal" href="#csv-fmt-params"><span class="std std-ref">Dialects and Formatting Parameters</span></a>.</p>
<p>Each row read from the csv file is returned as a list of strings. No
automatic data type conversion is performed unless the <a class="reference internal" href="#csv.QUOTE_NONNUMERIC" title="csv.QUOTE_NONNUMERIC"><code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_NONNUMERIC</span></code></a> format
option is specified (in which case unquoted fields are transformed into floats).</p>
<p>A short usage example:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="gp">>>> </span><span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'eggs.csv'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">csvfile</span><span class="p">:</span>
<span class="gp">... </span> <span class="n">spamreader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">csvfile</span><span class="p">,</span> <span class="n">delimiter</span><span class="o">=</span><span class="s1">' '</span><span class="p">,</span> <span class="n">quotechar</span><span class="o">=</span><span class="s1">'|'</span><span class="p">)</span>
<span class="gp">... </span> <span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">spamreader</span><span class="p">:</span>
<span class="gp">... </span> <span class="nb">print</span><span class="p">(</span><span class="s1">', '</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="n">row</span><span class="p">))</span>
<span class="go">Spam, Spam, Spam, Spam, Spam, Baked Beans</span>
<span class="go">Spam, Lovely Spam, Wonderful Spam</span>
</pre></div>
</div>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="csv.writer">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">writer</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">csvfile</span></span></em>, <em class="sig-param"><span class="positional-only-separator o"><abbr title="Positional-only parameter separator (PEP 570)"><span class="pre">/</span></abbr></span></em>, <em class="sig-param"><span class="n"><span class="pre">dialect</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'excel'</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">fmtparams</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.writer" title="Link to this definition">¶</a></dt>
<dd><p>Return a writer object responsible for converting the user's data into delimited
strings on the given file-like object. <em>csvfile</em> can be any object with a
<a class="reference internal" href="io.html#io.TextIOBase.write" title="io.TextIOBase.write"><code class="xref py py-meth docutils literal notranslate"><span class="pre">write()</span></code></a> method. If <em>csvfile</em> is a file object, it should be opened with
<code class="docutils literal notranslate"><span class="pre">newline=''</span></code> <a class="footnote-reference brackets" href="#id4" id="id2" role="doc-noteref"><span class="fn-bracket">[</span>1<span class="fn-bracket">]</span></a>. An optional <em>dialect</em>
parameter can be given which is used to define a set of parameters specific to a
particular CSV dialect. It may be an instance of a subclass of the
<a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a> class or one of the strings returned by the
<a class="reference internal" href="#csv.list_dialects" title="csv.list_dialects"><code class="xref py py-func docutils literal notranslate"><span class="pre">list_dialects()</span></code></a> function. The other optional <em>fmtparams</em> keyword arguments
can be given to override individual formatting parameters in the current
dialect. For full details about dialects and formatting parameters, see
the <a class="reference internal" href="#csv-fmt-params"><span class="std std-ref">Dialects and Formatting Parameters</span></a> section. To make it
as easy as possible to interface with modules which implement the DB API, the
value <a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal notranslate"><span class="pre">None</span></code></a> is written as the empty string. While this isn't a
reversible transformation, it makes it easier to dump SQL NULL data values to
CSV files without preprocessing the data returned from a <code class="docutils literal notranslate"><span class="pre">cursor.fetch*</span></code> call.
All other non-string data are stringified with <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-func docutils literal notranslate"><span class="pre">str()</span></code></a> before being written.</p>
<p>A short usage example:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'eggs.csv'</span><span class="p">,</span> <span class="s1">'w'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">csvfile</span><span class="p">:</span>
<span class="n">spamwriter</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">writer</span><span class="p">(</span><span class="n">csvfile</span><span class="p">,</span> <span class="n">delimiter</span><span class="o">=</span><span class="s1">' '</span><span class="p">,</span>
<span class="n">quotechar</span><span class="o">=</span><span class="s1">'|'</span><span class="p">,</span> <span class="n">quoting</span><span class="o">=</span><span class="n">csv</span><span class="o">.</span><span class="n">QUOTE_MINIMAL</span><span class="p">)</span>
<span class="n">spamwriter</span><span class="o">.</span><span class="n">writerow</span><span class="p">([</span><span class="s1">'Spam'</span><span class="p">]</span> <span class="o">*</span> <span class="mi">5</span> <span class="o">+</span> <span class="p">[</span><span class="s1">'Baked Beans'</span><span class="p">])</span>
<span class="n">spamwriter</span><span class="o">.</span><span class="n">writerow</span><span class="p">([</span><span class="s1">'Spam'</span><span class="p">,</span> <span class="s1">'Lovely Spam'</span><span class="p">,</span> <span class="s1">'Wonderful Spam'</span><span class="p">])</span>
</pre></div>
</div>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="csv.register_dialect">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">register_dialect</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span></em>, <em class="sig-param"><span class="positional-only-separator o"><abbr title="Positional-only parameter separator (PEP 570)"><span class="pre">/</span></abbr></span></em>, <em class="sig-param"><span class="n"><span class="pre">dialect</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'excel'</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">fmtparams</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.register_dialect" title="Link to this definition">¶</a></dt>
<dd><p>Associate <em>dialect</em> with <em>name</em>. <em>name</em> must be a string. The
dialect can be specified either by passing a sub-class of <a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a>, or
by <em>fmtparams</em> keyword arguments, or both, with keyword arguments overriding
parameters of the dialect. For full details about dialects and formatting
parameters, see section <a class="reference internal" href="#csv-fmt-params"><span class="std std-ref">Dialects and Formatting Parameters</span></a>.</p>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="csv.unregister_dialect">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">unregister_dialect</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.unregister_dialect" title="Link to this definition">¶</a></dt>
<dd><p>Delete the dialect associated with <em>name</em> from the dialect registry. An
<a class="reference internal" href="#csv.Error" title="csv.Error"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Error</span></code></a> is raised if <em>name</em> is not a registered dialect name.</p>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="csv.get_dialect">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">get_dialect</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.get_dialect" title="Link to this definition">¶</a></dt>
<dd><p>Return the dialect associated with <em>name</em>. An <a class="reference internal" href="#csv.Error" title="csv.Error"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Error</span></code></a> is raised if
<em>name</em> is not a registered dialect name. This function returns an immutable
<a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a>.</p>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="csv.list_dialects">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">list_dialects</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#csv.list_dialects" title="Link to this definition">¶</a></dt>
<dd><p>Return the names of all registered dialects.</p>
</dd></dl>
<dl class="py function">
<dt class="sig sig-object py" id="csv.field_size_limit">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">field_size_limit</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#csv.field_size_limit" title="Link to this definition">¶</a></dt>
<dt class="sig sig-object py">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">field_size_limit</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">new_limit</span></span></em><span class="sig-paren">)</span></dt>
<dd><p>Returns the current maximum field size allowed by the parser. If <em>new_limit</em> is
given, this becomes the new limit.</p>
</dd></dl>
<p>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> module defines the following classes:</p>
<dl class="py class">
<dt class="sig sig-object py" id="csv.DictReader">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">DictReader</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">f</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">fieldnames</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">restkey</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">restval</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">dialect</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'excel'</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kwds</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.DictReader" title="Link to this definition">¶</a></dt>
<dd><p>Create an object that operates like a regular reader but maps the
information in each row to a <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a> whose keys are given by the
optional <em>fieldnames</em> parameter.</p>
<p>The <em>fieldnames</em> parameter is a <a class="reference internal" href="../glossary.html#term-sequence"><span class="xref std std-term">sequence</span></a>. If <em>fieldnames</em> is
omitted, the values in the first row of file <em>f</em> will be used as the
fieldnames and will be omitted from the results. If
<em>fieldnames</em> is provided, they will be used and the first row will be
included in the results. Regardless of how the fieldnames are determined,
the dictionary preserves their original ordering.</p>
<p>If a row has more fields than fieldnames, the remaining data is put in a
list and stored with the fieldname specified by <em>restkey</em> (which defaults
to <code class="docutils literal notranslate"><span class="pre">None</span></code>). If a non-blank row has fewer fields than fieldnames, the
missing values are filled-in with the value of <em>restval</em> (which defaults
to <code class="docutils literal notranslate"><span class="pre">None</span></code>).</p>
<p>All other optional or keyword arguments are passed to the underlying
<a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> instance.</p>
<p>If the argument passed to <em>fieldnames</em> is an iterator, it will be coerced to a <a class="reference internal" href="stdtypes.html#list" title="list"><code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code></a>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">تغییر داده شده در نسخه 3.6: </span>Returned rows are now of type <code class="xref py py-class docutils literal notranslate"><span class="pre">OrderedDict</span></code>.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">تغییر داده شده در نسخه 3.8: </span>Returned rows are now of type <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>.</p>
</div>
<p>A short usage example:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="gp">>>> </span><span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'names.csv'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">csvfile</span><span class="p">:</span>
<span class="gp">... </span> <span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">DictReader</span><span class="p">(</span><span class="n">csvfile</span><span class="p">)</span>
<span class="gp">... </span> <span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">reader</span><span class="p">:</span>
<span class="gp">... </span> <span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">[</span><span class="s1">'first_name'</span><span class="p">],</span> <span class="n">row</span><span class="p">[</span><span class="s1">'last_name'</span><span class="p">])</span>
<span class="gp">...</span>
<span class="go">Eric Idle</span>
<span class="go">John Cleese</span>
<span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">)</span>
<span class="go">{'first_name': 'John', 'last_name': 'Cleese'}</span>
</pre></div>
</div>
</dd></dl>
<dl class="py class">
<dt class="sig sig-object py" id="csv.DictWriter">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">DictWriter</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">f</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">fieldnames</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">restval</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">''</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">extrasaction</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'raise'</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">dialect</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'excel'</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span><span class="n"><span class="pre">args</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kwds</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.DictWriter" title="Link to this definition">¶</a></dt>
<dd><p>Create an object which operates like a regular writer but maps dictionaries
onto output rows. The <em>fieldnames</em> parameter is a <a class="reference internal" href="collections.abc.html#module-collections.abc" title="collections.abc: Abstract base classes for containers"><code class="xref py py-mod docutils literal notranslate"><span class="pre">sequence</span></code></a> of keys that identify the order in which values in the
dictionary passed to the <a class="reference internal" href="#csv.csvwriter.writerow" title="csv.csvwriter.writerow"><code class="xref py py-meth docutils literal notranslate"><span class="pre">writerow()</span></code></a> method are written to file
<em>f</em>. The optional <em>restval</em> parameter specifies the value to be
written if the dictionary is missing a key in <em>fieldnames</em>. If the
dictionary passed to the <code class="xref py py-meth docutils literal notranslate"><span class="pre">writerow()</span></code> method contains a key not found in
<em>fieldnames</em>, the optional <em>extrasaction</em> parameter indicates what action to
take.
If it is set to <code class="docutils literal notranslate"><span class="pre">'raise'</span></code>, the default value, a <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a>
is raised.
If it is set to <code class="docutils literal notranslate"><span class="pre">'ignore'</span></code>, extra values in the dictionary are ignored.
Any other optional or keyword arguments are passed to the underlying
<a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> instance.</p>
<p>Note that unlike the <a class="reference internal" href="#csv.DictReader" title="csv.DictReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">DictReader</span></code></a> class, the <em>fieldnames</em> parameter
of the <code class="xref py py-class docutils literal notranslate"><span class="pre">DictWriter</span></code> class is not optional.</p>
<p>If the argument passed to <em>fieldnames</em> is an iterator, it will be coerced to a <a class="reference internal" href="stdtypes.html#list" title="list"><code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code></a>.</p>
<p>A short usage example:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'names.csv'</span><span class="p">,</span> <span class="s1">'w'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">csvfile</span><span class="p">:</span>
<span class="n">fieldnames</span> <span class="o">=</span> <span class="p">[</span><span class="s1">'first_name'</span><span class="p">,</span> <span class="s1">'last_name'</span><span class="p">]</span>
<span class="n">writer</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">DictWriter</span><span class="p">(</span><span class="n">csvfile</span><span class="p">,</span> <span class="n">fieldnames</span><span class="o">=</span><span class="n">fieldnames</span><span class="p">)</span>
<span class="n">writer</span><span class="o">.</span><span class="n">writeheader</span><span class="p">()</span>
<span class="n">writer</span><span class="o">.</span><span class="n">writerow</span><span class="p">({</span><span class="s1">'first_name'</span><span class="p">:</span> <span class="s1">'Baked'</span><span class="p">,</span> <span class="s1">'last_name'</span><span class="p">:</span> <span class="s1">'Beans'</span><span class="p">})</span>
<span class="n">writer</span><span class="o">.</span><span class="n">writerow</span><span class="p">({</span><span class="s1">'first_name'</span><span class="p">:</span> <span class="s1">'Lovely'</span><span class="p">,</span> <span class="s1">'last_name'</span><span class="p">:</span> <span class="s1">'Spam'</span><span class="p">})</span>
<span class="n">writer</span><span class="o">.</span><span class="n">writerow</span><span class="p">({</span><span class="s1">'first_name'</span><span class="p">:</span> <span class="s1">'Wonderful'</span><span class="p">,</span> <span class="s1">'last_name'</span><span class="p">:</span> <span class="s1">'Spam'</span><span class="p">})</span>
</pre></div>
</div>
</dd></dl>
<dl class="py class">
<dt class="sig sig-object py" id="csv.Dialect">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">Dialect</span></span><a class="headerlink" href="#csv.Dialect" title="Link to this definition">¶</a></dt>
<dd><p>The <code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code> class is a container class whose attributes contain
information for how to handle doublequotes, whitespace, delimiters, etc.
Due to the lack of a strict CSV specification, different applications
produce subtly different CSV data. <code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code> instances define how
<a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> and <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> instances behave.</p>
<p>All available <code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code> names are returned by <a class="reference internal" href="#csv.list_dialects" title="csv.list_dialects"><code class="xref py py-func docutils literal notranslate"><span class="pre">list_dialects()</span></code></a>,
and they can be registered with specific <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> and <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a>
classes through their initializer (<code class="docutils literal notranslate"><span class="pre">__init__</span></code>) functions like this:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'students.csv'</span><span class="p">,</span> <span class="s1">'w'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">csvfile</span><span class="p">:</span>
<span class="n">writer</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">writer</span><span class="p">(</span><span class="n">csvfile</span><span class="p">,</span> <span class="n">dialect</span><span class="o">=</span><span class="s1">'unix'</span><span class="p">)</span>
</pre></div>
</div>
</dd></dl>
<dl class="py class">
<dt class="sig sig-object py" id="csv.excel">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">excel</span></span><a class="headerlink" href="#csv.excel" title="Link to this definition">¶</a></dt>
<dd><p>The <code class="xref py py-class docutils literal notranslate"><span class="pre">excel</span></code> class defines the usual properties of an Excel-generated CSV
file. It is registered with the dialect name <code class="docutils literal notranslate"><span class="pre">'excel'</span></code>.</p>
</dd></dl>
<dl class="py class">
<dt class="sig sig-object py" id="csv.excel_tab">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">excel_tab</span></span><a class="headerlink" href="#csv.excel_tab" title="Link to this definition">¶</a></dt>
<dd><p>The <code class="xref py py-class docutils literal notranslate"><span class="pre">excel_tab</span></code> class defines the usual properties of an Excel-generated
TAB-delimited file. It is registered with the dialect name <code class="docutils literal notranslate"><span class="pre">'excel-tab'</span></code>.</p>
</dd></dl>
<dl class="py class">
<dt class="sig sig-object py" id="csv.unix_dialect">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">unix_dialect</span></span><a class="headerlink" href="#csv.unix_dialect" title="Link to this definition">¶</a></dt>
<dd><p>The <code class="xref py py-class docutils literal notranslate"><span class="pre">unix_dialect</span></code> class defines the usual properties of a CSV file
generated on UNIX systems, i.e. using <code class="docutils literal notranslate"><span class="pre">'\n'</span></code> as line terminator and quoting
all fields. It is registered with the dialect name <code class="docutils literal notranslate"><span class="pre">'unix'</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.2.</span></p>
</div>
</dd></dl>
<dl class="py class">
<dt class="sig sig-object py" id="csv.Sniffer">
<em class="property"><span class="k"><span class="pre">class</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">Sniffer</span></span><a class="headerlink" href="#csv.Sniffer" title="Link to this definition">¶</a></dt>
<dd><p>The <code class="xref py py-class docutils literal notranslate"><span class="pre">Sniffer</span></code> class is used to deduce the format of a CSV file.</p>
<p>The <code class="xref py py-class docutils literal notranslate"><span class="pre">Sniffer</span></code> class provides two methods:</p>
<dl class="py method">
<dt class="sig sig-object py" id="csv.Sniffer.sniff">
<span class="sig-name descname"><span class="pre">sniff</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">sample</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">delimiters</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.Sniffer.sniff" title="Link to this definition">¶</a></dt>
<dd><p>Analyze the given <em>sample</em> and return a <a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a> subclass
reflecting the parameters found. If the optional <em>delimiters</em> parameter
is given, it is interpreted as a string containing possible valid
delimiter characters.</p>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="csv.Sniffer.has_header">
<span class="sig-name descname"><span class="pre">has_header</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">sample</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.Sniffer.has_header" title="Link to this definition">¶</a></dt>
<dd><p>Analyze the sample text (presumed to be in CSV format) and return
<a class="reference internal" href="constants.html#True" title="True"><code class="xref py py-const docutils literal notranslate"><span class="pre">True</span></code></a> if the first row appears to be a series of column headers.
Inspecting each column, one of two key criteria will be considered to
estimate if the sample contains a header:</p>
<ul class="simple">
<li><p>the second through n-th rows contain numeric values</p></li>
<li><p>the second through n-th rows contain strings where at least one value's
length differs from that of the putative header of that column.</p></li>
</ul>
<p>Twenty-one rows after the header are sampled; if more than half of the
columns + rows meet the criteria, <a class="reference internal" href="constants.html#True" title="True"><code class="xref py py-const docutils literal notranslate"><span class="pre">True</span></code></a> is returned.</p>
</dd></dl>
<div class="admonition note">
<p class="admonition-title">توجه</p>
<p>This method is a rough heuristic and may produce both false positives and
negatives.</p>
</div>
</dd></dl>
<p>An example for <a class="reference internal" href="#csv.Sniffer" title="csv.Sniffer"><code class="xref py py-class docutils literal notranslate"><span class="pre">Sniffer</span></code></a> use:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'example.csv'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">csvfile</span><span class="p">:</span>
<span class="n">dialect</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">Sniffer</span><span class="p">()</span><span class="o">.</span><span class="n">sniff</span><span class="p">(</span><span class="n">csvfile</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="mi">1024</span><span class="p">))</span>
<span class="n">csvfile</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">csvfile</span><span class="p">,</span> <span class="n">dialect</span><span class="p">)</span>
<span class="c1"># ... process CSV file contents here ...</span>
</pre></div>
</div>
<p id="csv-constants">The <code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> module defines the following constants:</p>
<dl class="py data">
<dt class="sig sig-object py" id="csv.QUOTE_ALL">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">QUOTE_ALL</span></span><a class="headerlink" href="#csv.QUOTE_ALL" title="Link to this definition">¶</a></dt>
<dd><p>Instructs <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects to quote all fields.</p>
</dd></dl>
<dl class="py data">
<dt class="sig sig-object py" id="csv.QUOTE_MINIMAL">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">QUOTE_MINIMAL</span></span><a class="headerlink" href="#csv.QUOTE_MINIMAL" title="Link to this definition">¶</a></dt>
<dd><p>Instructs <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects to only quote those fields which contain
special characters such as <em>delimiter</em>, <em>quotechar</em>, <code class="docutils literal notranslate"><span class="pre">'\r'</span></code>, <code class="docutils literal notranslate"><span class="pre">'\n'</span></code>
or any of the characters in <em>lineterminator</em>.</p>
</dd></dl>
<dl class="py data">
<dt class="sig sig-object py" id="csv.QUOTE_NONNUMERIC">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">QUOTE_NONNUMERIC</span></span><a class="headerlink" href="#csv.QUOTE_NONNUMERIC" title="Link to this definition">¶</a></dt>
<dd><p>Instructs <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects to quote all non-numeric fields.</p>
<p>Instructs <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> objects to convert all non-quoted fields to type <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>.</p>
<div class="admonition note">
<p class="admonition-title">توجه</p>
<p>Some numeric types, such as <a class="reference internal" href="functions.html#bool" title="bool"><code class="xref py py-class docutils literal notranslate"><span class="pre">bool</span></code></a>, <a class="reference internal" href="fractions.html#fractions.Fraction" title="fractions.Fraction"><code class="xref py py-class docutils literal notranslate"><span class="pre">Fraction</span></code></a>,
or <a class="reference internal" href="enum.html#enum.IntEnum" title="enum.IntEnum"><code class="xref py py-class docutils literal notranslate"><span class="pre">IntEnum</span></code></a>, have a string representation that cannot be
converted to <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>.
They cannot be read in the <code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_NONNUMERIC</span></code> and
<a class="reference internal" href="#csv.QUOTE_STRINGS" title="csv.QUOTE_STRINGS"><code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_STRINGS</span></code></a> modes.</p>
</div>
</dd></dl>
<dl class="py data">
<dt class="sig sig-object py" id="csv.QUOTE_NONE">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">QUOTE_NONE</span></span><a class="headerlink" href="#csv.QUOTE_NONE" title="Link to this definition">¶</a></dt>
<dd><p>Instructs <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects to never quote fields.
When the current <em>delimiter</em>, <em>quotechar</em>, <em>escapechar</em>, <code class="docutils literal notranslate"><span class="pre">'\r'</span></code>, <code class="docutils literal notranslate"><span class="pre">'\n'</span></code>
or any of the characters in <em>lineterminator</em> occurs in output data
it is preceded by the current <em>escapechar</em> character.
If <em>escapechar</em> is not set, the writer will raise <a class="reference internal" href="#csv.Error" title="csv.Error"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Error</span></code></a> if
any characters that require escaping are encountered.
Set <em>quotechar</em> to <code class="docutils literal notranslate"><span class="pre">None</span></code> to prevent its escaping.</p>
<p>Instructs <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> objects to perform no special processing of quote characters.</p>
</dd></dl>
<dl class="py data">
<dt class="sig sig-object py" id="csv.QUOTE_NOTNULL">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">QUOTE_NOTNULL</span></span><a class="headerlink" href="#csv.QUOTE_NOTNULL" title="Link to this definition">¶</a></dt>
<dd><p>Instructs <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects to quote all fields which are not
<code class="docutils literal notranslate"><span class="pre">None</span></code>. This is similar to <a class="reference internal" href="#csv.QUOTE_ALL" title="csv.QUOTE_ALL"><code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_ALL</span></code></a>, except that if a
field value is <code class="docutils literal notranslate"><span class="pre">None</span></code> an empty (unquoted) string is written.</p>
<p>Instructs <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> objects to interpret an empty (unquoted) field
as <code class="docutils literal notranslate"><span class="pre">None</span></code> and to otherwise behave as <a class="reference internal" href="#csv.QUOTE_ALL" title="csv.QUOTE_ALL"><code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_ALL</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.12.</span></p>
</div>
</dd></dl>
<dl class="py data">
<dt class="sig sig-object py" id="csv.QUOTE_STRINGS">
<span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">QUOTE_STRINGS</span></span><a class="headerlink" href="#csv.QUOTE_STRINGS" title="Link to this definition">¶</a></dt>
<dd><p>Instructs <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects to always place quotes around fields
which are strings. This is similar to <a class="reference internal" href="#csv.QUOTE_NONNUMERIC" title="csv.QUOTE_NONNUMERIC"><code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_NONNUMERIC</span></code></a>, except that if a
field value is <code class="docutils literal notranslate"><span class="pre">None</span></code> an empty (unquoted) string is written.</p>
<p>Instructs <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> objects to interpret an empty (unquoted) string as <code class="docutils literal notranslate"><span class="pre">None</span></code> and
to otherwise behave as <a class="reference internal" href="#csv.QUOTE_NONNUMERIC" title="csv.QUOTE_NONNUMERIC"><code class="xref py py-data docutils literal notranslate"><span class="pre">QUOTE_NONNUMERIC</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.12.</span></p>
</div>
</dd></dl>
<p>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> module defines the following exception:</p>
<dl class="py exception">
<dt class="sig sig-object py" id="csv.Error">
<em class="property"><span class="k"><span class="pre">exception</span></span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">csv.</span></span><span class="sig-name descname"><span class="pre">Error</span></span><a class="headerlink" href="#csv.Error" title="Link to this definition">¶</a></dt>
<dd><p>Raised by any of the functions when an error is detected.</p>
</dd></dl>
</section>
<section id="dialects-and-formatting-parameters">
<span id="csv-fmt-params"></span><h2>Dialects and Formatting Parameters<a class="headerlink" href="#dialects-and-formatting-parameters" title="Link to this heading">¶</a></h2>
<p>To make it easier to specify the format of input and output records, specific
formatting parameters are grouped together into dialects. A dialect is a
subclass of the <a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a> class containing various attributes
describing the format of the CSV file. When creating <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> or
<a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects, the programmer can specify a string or a subclass of
the <code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code> class as the dialect parameter. In addition to, or instead
of, the <em>dialect</em> parameter, the programmer can also specify individual
formatting parameters, which have the same names as the attributes defined below
for the <code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code> class.</p>
<p>Dialects support the following attributes:</p>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.delimiter">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">delimiter</span></span><a class="headerlink" href="#csv.Dialect.delimiter" title="Link to this definition">¶</a></dt>
<dd><p>A one-character string used to separate fields. It defaults to <code class="docutils literal notranslate"><span class="pre">','</span></code>.</p>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.doublequote">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">doublequote</span></span><a class="headerlink" href="#csv.Dialect.doublequote" title="Link to this definition">¶</a></dt>
<dd><p>Controls how instances of <em>quotechar</em> appearing inside a field should
themselves be quoted. When <a class="reference internal" href="constants.html#True" title="True"><code class="xref py py-const docutils literal notranslate"><span class="pre">True</span></code></a>, the character is doubled. When
<a class="reference internal" href="constants.html#False" title="False"><code class="xref py py-const docutils literal notranslate"><span class="pre">False</span></code></a>, the <em>escapechar</em> is used as a prefix to the <em>quotechar</em>. It
defaults to <code class="xref py py-const docutils literal notranslate"><span class="pre">True</span></code>.</p>
<p>On output, if <em>doublequote</em> is <a class="reference internal" href="constants.html#False" title="False"><code class="xref py py-const docutils literal notranslate"><span class="pre">False</span></code></a> and no <em>escapechar</em> is set,
<a class="reference internal" href="#csv.Error" title="csv.Error"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Error</span></code></a> is raised if a <em>quotechar</em> is found in a field.</p>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.escapechar">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">escapechar</span></span><a class="headerlink" href="#csv.Dialect.escapechar" title="Link to this definition">¶</a></dt>
<dd><p>A one-character string used by the writer to escape characters that
require escaping:</p>
<blockquote>
<div><ul class="simple">
<li><p>the <em>delimiter</em>, the <em>quotechar</em>, <code class="docutils literal notranslate"><span class="pre">'\r'</span></code>, <code class="docutils literal notranslate"><span class="pre">'\n'</span></code> and any of the
characters in <em>lineterminator</em> are escaped if <em>quoting</em> is set to
<a class="reference internal" href="#csv.QUOTE_NONE" title="csv.QUOTE_NONE"><code class="xref py py-const docutils literal notranslate"><span class="pre">QUOTE_NONE</span></code></a>;</p></li>
<li><p>the <em>quotechar</em> is escaped if <em>doublequote</em> is <a class="reference internal" href="constants.html#False" title="False"><code class="xref py py-const docutils literal notranslate"><span class="pre">False</span></code></a>;</p></li>
<li><p>the <em>escapechar</em> itself.</p></li>
</ul>
</div></blockquote>
<p>On reading, the <em>escapechar</em> removes any special meaning from
the following character. It defaults to <a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal notranslate"><span class="pre">None</span></code></a>, which disables escaping.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">تغییر داده شده در نسخه 3.11: </span>An empty <em>escapechar</em> is not allowed.</p>
</div>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.lineterminator">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">lineterminator</span></span><a class="headerlink" href="#csv.Dialect.lineterminator" title="Link to this definition">¶</a></dt>
<dd><p>The string used to terminate lines produced by the <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a>. It defaults
to <code class="docutils literal notranslate"><span class="pre">'\r\n'</span></code>.</p>
<div class="admonition note">
<p class="admonition-title">توجه</p>
<p>The <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-class docutils literal notranslate"><span class="pre">reader</span></code></a> is hard-coded to recognise either <code class="docutils literal notranslate"><span class="pre">'\r'</span></code> or <code class="docutils literal notranslate"><span class="pre">'\n'</span></code> as
end-of-line, and ignores <em>lineterminator</em>. This behavior may change in the
future.</p>
</div>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.quotechar">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">quotechar</span></span><a class="headerlink" href="#csv.Dialect.quotechar" title="Link to this definition">¶</a></dt>
<dd><p>A one-character string used to quote fields containing special characters,
such as the <em>delimiter</em> or the <em>quotechar</em>, or which contain new-line
characters (<code class="docutils literal notranslate"><span class="pre">'\r'</span></code>, <code class="docutils literal notranslate"><span class="pre">'\n'</span></code> or any of the characters in <em>lineterminator</em>).
It defaults to <code class="docutils literal notranslate"><span class="pre">'"'</span></code>.
Can be set to <code class="docutils literal notranslate"><span class="pre">None</span></code> to prevent escaping <code class="docutils literal notranslate"><span class="pre">'"'</span></code> if <em>quoting</em> is set
to <a class="reference internal" href="#csv.QUOTE_NONE" title="csv.QUOTE_NONE"><code class="xref py py-const docutils literal notranslate"><span class="pre">QUOTE_NONE</span></code></a>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">تغییر داده شده در نسخه 3.11: </span>An empty <em>quotechar</em> is not allowed.</p>
</div>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.quoting">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">quoting</span></span><a class="headerlink" href="#csv.Dialect.quoting" title="Link to this definition">¶</a></dt>
<dd><p>Controls when quotes should be generated by the writer and recognised by the
reader. It can take on any of the <a class="reference internal" href="#csv-constants"><span class="std std-ref">QUOTE_* constants</span></a>
and defaults to <a class="reference internal" href="#csv.QUOTE_MINIMAL" title="csv.QUOTE_MINIMAL"><code class="xref py py-const docutils literal notranslate"><span class="pre">QUOTE_MINIMAL</span></code></a> if <em>quotechar</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>,
and <a class="reference internal" href="#csv.QUOTE_NONE" title="csv.QUOTE_NONE"><code class="xref py py-const docutils literal notranslate"><span class="pre">QUOTE_NONE</span></code></a> otherwise.</p>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.skipinitialspace">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">skipinitialspace</span></span><a class="headerlink" href="#csv.Dialect.skipinitialspace" title="Link to this definition">¶</a></dt>
<dd><p>When <a class="reference internal" href="constants.html#True" title="True"><code class="xref py py-const docutils literal notranslate"><span class="pre">True</span></code></a>, spaces immediately following the <em>delimiter</em> are ignored.
The default is <a class="reference internal" href="constants.html#False" title="False"><code class="xref py py-const docutils literal notranslate"><span class="pre">False</span></code></a>. When combining <code class="docutils literal notranslate"><span class="pre">delimiter='</span> <span class="pre">'</span></code> with
<code class="docutils literal notranslate"><span class="pre">skipinitialspace=True</span></code>, unquoted empty fields are not allowed.</p>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.Dialect.strict">
<span class="sig-prename descclassname"><span class="pre">Dialect.</span></span><span class="sig-name descname"><span class="pre">strict</span></span><a class="headerlink" href="#csv.Dialect.strict" title="Link to this definition">¶</a></dt>
<dd><p>When <code class="docutils literal notranslate"><span class="pre">True</span></code>, raise exception <a class="reference internal" href="#csv.Error" title="csv.Error"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Error</span></code></a> on bad CSV input.
The default is <code class="docutils literal notranslate"><span class="pre">False</span></code>.</p>
</dd></dl>
</section>
<section id="reader-objects">
<span id="id3"></span><h2>Reader Objects<a class="headerlink" href="#reader-objects" title="Link to this heading">¶</a></h2>
<p>Reader objects (<a class="reference internal" href="#csv.DictReader" title="csv.DictReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">DictReader</span></code></a> instances and objects returned by the
<a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-func docutils literal notranslate"><span class="pre">reader()</span></code></a> function) have the following public methods:</p>
<dl class="py method">
<dt class="sig sig-object py" id="csv.csvreader.__next__">
<span class="sig-prename descclassname"><span class="pre">csvreader.</span></span><span class="sig-name descname"><span class="pre">__next__</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#csv.csvreader.__next__" title="Link to this definition">¶</a></dt>
<dd><p>Return the next row of the reader's iterable object as a list (if the object
was returned from <a class="reference internal" href="#csv.reader" title="csv.reader"><code class="xref py py-func docutils literal notranslate"><span class="pre">reader()</span></code></a>) or a dict (if it is a <a class="reference internal" href="#csv.DictReader" title="csv.DictReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">DictReader</span></code></a>
instance), parsed according to the current <a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a>. Usually you
should call this as <code class="docutils literal notranslate"><span class="pre">next(reader)</span></code>.</p>
</dd></dl>
<p>Reader objects have the following public attributes:</p>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.csvreader.dialect">
<span class="sig-prename descclassname"><span class="pre">csvreader.</span></span><span class="sig-name descname"><span class="pre">dialect</span></span><a class="headerlink" href="#csv.csvreader.dialect" title="Link to this definition">¶</a></dt>
<dd><p>A read-only description of the dialect in use by the parser.</p>
</dd></dl>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.csvreader.line_num">
<span class="sig-prename descclassname"><span class="pre">csvreader.</span></span><span class="sig-name descname"><span class="pre">line_num</span></span><a class="headerlink" href="#csv.csvreader.line_num" title="Link to this definition">¶</a></dt>
<dd><p>The number of lines read from the source iterator. This is not the same as the
number of records returned, as records can span multiple lines.</p>
</dd></dl>
<p>DictReader objects have the following public attribute:</p>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.DictReader.fieldnames">
<span class="sig-prename descclassname"><span class="pre">DictReader.</span></span><span class="sig-name descname"><span class="pre">fieldnames</span></span><a class="headerlink" href="#csv.DictReader.fieldnames" title="Link to this definition">¶</a></dt>
<dd><p>If not passed as a parameter when creating the object, this attribute is
initialized upon first access or when the first record is read from the
file.</p>
</dd></dl>
</section>
<section id="writer-objects">
<h2>Writer Objects<a class="headerlink" href="#writer-objects" title="Link to this heading">¶</a></h2>
<p><a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code></a> objects (<a class="reference internal" href="#csv.DictWriter" title="csv.DictWriter"><code class="xref py py-class docutils literal notranslate"><span class="pre">DictWriter</span></code></a> instances and objects returned by
the <a class="reference internal" href="#csv.writer" title="csv.writer"><code class="xref py py-func docutils literal notranslate"><span class="pre">writer()</span></code></a> function) have the following public methods. A <em>row</em> must be
an iterable of strings or numbers for <code class="xref py py-class docutils literal notranslate"><span class="pre">writer</span></code> objects and a dictionary
mapping fieldnames to strings or numbers (by passing them through <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-func docutils literal notranslate"><span class="pre">str()</span></code></a>
first) for <code class="xref py py-class docutils literal notranslate"><span class="pre">DictWriter</span></code> objects. Note that complex numbers are written
out surrounded by parens. This may cause some problems for other programs which
read CSV files (assuming they support complex numbers at all).</p>
<dl class="py method">
<dt class="sig sig-object py" id="csv.csvwriter.writerow">
<span class="sig-prename descclassname"><span class="pre">csvwriter.</span></span><span class="sig-name descname"><span class="pre">writerow</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">row</span></span></em>, <em class="sig-param"><span class="positional-only-separator o"><abbr title="Positional-only parameter separator (PEP 570)"><span class="pre">/</span></abbr></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.csvwriter.writerow" title="Link to this definition">¶</a></dt>
<dd><p>Write the <em>row</em> parameter to the writer's file object, formatted according
to the current <a class="reference internal" href="#csv.Dialect" title="csv.Dialect"><code class="xref py py-class docutils literal notranslate"><span class="pre">Dialect</span></code></a>. Return the return value of the call to the
<em>write</em> method of the underlying file object.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">تغییر داده شده در نسخه 3.5: </span>Added support of arbitrary iterables.</p>
</div>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="csv.csvwriter.writerows">
<span class="sig-prename descclassname"><span class="pre">csvwriter.</span></span><span class="sig-name descname"><span class="pre">writerows</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">rows</span></span></em>, <em class="sig-param"><span class="positional-only-separator o"><abbr title="Positional-only parameter separator (PEP 570)"><span class="pre">/</span></abbr></span></em><span class="sig-paren">)</span><a class="headerlink" href="#csv.csvwriter.writerows" title="Link to this definition">¶</a></dt>
<dd><p>Write all elements in <em>rows</em> (an iterable of <em>row</em> objects as described
above) to the writer's file object, formatted according to the current
dialect.</p>
</dd></dl>
<p>Writer objects have the following public attribute:</p>
<dl class="py attribute">
<dt class="sig sig-object py" id="csv.csvwriter.dialect">
<span class="sig-prename descclassname"><span class="pre">csvwriter.</span></span><span class="sig-name descname"><span class="pre">dialect</span></span><a class="headerlink" href="#csv.csvwriter.dialect" title="Link to this definition">¶</a></dt>
<dd><p>A read-only description of the dialect in use by the writer.</p>
</dd></dl>
<p>DictWriter objects have the following public method:</p>
<dl class="py method">
<dt class="sig sig-object py" id="csv.DictWriter.writeheader">
<span class="sig-prename descclassname"><span class="pre">DictWriter.</span></span><span class="sig-name descname"><span class="pre">writeheader</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#csv.DictWriter.writeheader" title="Link to this definition">¶</a></dt>
<dd><p>Write a row with the field names (as specified in the constructor) to
the writer's file object, formatted according to the current dialect. Return
the return value of the <a class="reference internal" href="#csv.csvwriter.writerow" title="csv.csvwriter.writerow"><code class="xref py py-meth docutils literal notranslate"><span class="pre">csvwriter.writerow()</span></code></a> call used internally.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.2.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">تغییر داده شده در نسخه 3.8: </span><code class="xref py py-meth docutils literal notranslate"><span class="pre">writeheader()</span></code> now also returns the value returned by
the <a class="reference internal" href="#csv.csvwriter.writerow" title="csv.csvwriter.writerow"><code class="xref py py-meth docutils literal notranslate"><span class="pre">csvwriter.writerow()</span></code></a> method it uses internally.</p>
</div>
</dd></dl>
</section>
<section id="examples">
<span id="csv-examples"></span><h2>Examples<a class="headerlink" href="#examples" title="Link to this heading">¶</a></h2>
<p>The simplest example of reading a CSV file:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'some.csv'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">reader</span><span class="p">:</span>
<span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">)</span>
</pre></div>
</div>
<p>Reading a file with an alternate format:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'passwd'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="n">delimiter</span><span class="o">=</span><span class="s1">':'</span><span class="p">,</span> <span class="n">quoting</span><span class="o">=</span><span class="n">csv</span><span class="o">.</span><span class="n">QUOTE_NONE</span><span class="p">)</span>
<span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">reader</span><span class="p">:</span>
<span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">)</span>
</pre></div>
</div>
<p>The corresponding simplest possible writing example is:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'some.csv'</span><span class="p">,</span> <span class="s1">'w'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">writer</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">writer</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="n">writer</span><span class="o">.</span><span class="n">writerows</span><span class="p">(</span><span class="n">someiterable</span><span class="p">)</span>
</pre></div>
</div>
<p>Since <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-func docutils literal notranslate"><span class="pre">open()</span></code></a> is used to open a CSV file for reading, the file
will by default be decoded into unicode using the system default
encoding (see <a class="reference internal" href="locale.html#locale.getencoding" title="locale.getencoding"><code class="xref py py-func docutils literal notranslate"><span class="pre">locale.getencoding()</span></code></a>). To decode a file
using a different encoding, use the <code class="docutils literal notranslate"><span class="pre">encoding</span></code> argument of open:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'some.csv'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">,</span> <span class="n">encoding</span><span class="o">=</span><span class="s1">'utf-8'</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">reader</span><span class="p">:</span>
<span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">)</span>
</pre></div>
</div>
<p>The same applies to writing in something other than the system default
encoding: specify the encoding argument when opening the output file.</p>
<p>Registering a new dialect:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="n">csv</span><span class="o">.</span><span class="n">register_dialect</span><span class="p">(</span><span class="s1">'unixpwd'</span><span class="p">,</span> <span class="n">delimiter</span><span class="o">=</span><span class="s1">':'</span><span class="p">,</span> <span class="n">quoting</span><span class="o">=</span><span class="n">csv</span><span class="o">.</span><span class="n">QUOTE_NONE</span><span class="p">)</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s1">'passwd'</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">f</span><span class="p">,</span> <span class="s1">'unixpwd'</span><span class="p">)</span>
</pre></div>
</div>
<p>A slightly more advanced use of the reader --- catching and reporting errors:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span><span class="o">,</span><span class="w"> </span><span class="nn">sys</span>
<span class="n">filename</span> <span class="o">=</span> <span class="s1">'some.csv'</span>
<span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="n">filename</span><span class="p">,</span> <span class="n">newline</span><span class="o">=</span><span class="s1">''</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="n">reader</span> <span class="o">=</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">(</span><span class="n">f</span><span class="p">)</span>
<span class="k">try</span><span class="p">:</span>
<span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">reader</span><span class="p">:</span>
<span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">)</span>
<span class="k">except</span> <span class="n">csv</span><span class="o">.</span><span class="n">Error</span> <span class="k">as</span> <span class="n">e</span><span class="p">:</span>
<span class="n">sys</span><span class="o">.</span><span class="n">exit</span><span class="p">(</span><span class="sa">f</span><span class="s1">'file </span><span class="si">{</span><span class="n">filename</span><span class="si">}</span><span class="s1">, line </span><span class="si">{</span><span class="n">reader</span><span class="o">.</span><span class="n">line_num</span><span class="si">}</span><span class="s1">: </span><span class="si">{</span><span class="n">e</span><span class="si">}</span><span class="s1">'</span><span class="p">)</span>
</pre></div>
</div>
<p>And while the module doesn't directly support parsing strings, it can easily be
done:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span><span class="w"> </span><span class="nn">csv</span>
<span class="k">for</span> <span class="n">row</span> <span class="ow">in</span> <span class="n">csv</span><span class="o">.</span><span class="n">reader</span><span class="p">([</span><span class="s1">'one,two,three'</span><span class="p">]):</span>
<span class="nb">print</span><span class="p">(</span><span class="n">row</span><span class="p">)</span>
</pre></div>
</div>
<p class="rubric">Footnotes</p>
<aside class="footnote-list brackets">
<aside class="footnote brackets" id="id4" role="doc-footnote">
<span class="label"><span class="fn-bracket">[</span>1<span class="fn-bracket">]</span></span>
<span class="backrefs">(<a role="doc-backlink" href="#id1">1</a>,<a role="doc-backlink" href="#id2">2</a>)</span>
<p>If <code class="docutils literal notranslate"><span class="pre">newline=''</span></code> is not specified, newlines embedded inside quoted fields
will not be interpreted correctly, and on platforms that use <code class="docutils literal notranslate"><span class="pre">\r\n</span></code> line endings
on write an extra <code class="docutils literal notranslate"><span class="pre">\r</span></code> will be added. It should always be safe to specify
<code class="docutils literal notranslate"><span class="pre">newline=''</span></code>, since the csv module does its own
(<a class="reference internal" href="../glossary.html#term-universal-newlines"><span class="xref std std-term">universal</span></a>) newline handling.</p>
</aside>
</aside>
</section>
</section>
<div class="clearer"></div>
</div>
</div>
</div>
<div class="sphinxsidebar" role="navigation" aria-label="Main">
<div class="sphinxsidebarwrapper">
<div>
<h3><a href="../contents.html">فهرست عناوین</a></h3>
<ul>
<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">csv</span></code> --- CSV File Reading and Writing</a><ul>
<li><a class="reference internal" href="#module-contents">Module Contents</a></li>
<li><a class="reference internal" href="#dialects-and-formatting-parameters">Dialects and Formatting Parameters</a></li>
<li><a class="reference internal" href="#reader-objects">Reader Objects</a></li>
<li><a class="reference internal" href="#writer-objects">Writer Objects</a></li>
<li><a class="reference internal" href="#examples">Examples</a></li>
</ul>
</li>
</ul>
</div>
<div>
<h4>موضوع قبلی</h4>
<p class="topless"><a href="fileformats.html"
title="فصل قبلی">File Formats</a></p>
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