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Make CSV import/export compatible across Python versions (also RDBMS journals) (issue 2550976, issue 2550975).
The roundup-admin export and import commands are used for migrating
between different database backends. It is desirable that they should
be usable also for migrations between Python 2 and Python 3, and in
some cases (e.g. with the anydbm backend) this may be required.
To be usable for such migrations, the format of the generated CSV
files needs to be stable, meaning the same as currently used with
Python 2. The export process uses repr() to produce the fields in the
CSV files and eval() to convert them back to Python data structures.
repr() of strings with non-ASCII characters produces different results
for Python 2 and Python 3.
This patch adds repr_export and eval_import functions to
roundup/anypy/strings.py which provide the required operations that
are just repr() and eval() in Python 2, but are more complicated in
Python 3 to use data representations compatible with Python 2. These
functions are then used in the required places for export and import.
repr() and eval() are also used in storing the dict of changed values
in the journal for the RDBMS backends. It is similarly desirable that
the database be compatible between Python 2 and Python 3, so that
export and import do not need to be used for a migration between
Python versions for non-anydbm back ends. Thus, this patch changes
rdbms_common.py in the places involved in storing journals in the
database, not just in those involved in import/export.
Given this patch, import/export with non-ASCII characters appear based
on some limited testing to work across Python versions, and an
instance using the sqlite backend appears to be compatible between
Python versions without needing import/export, *if* the sessions/otks
databases (which use anydbm) are deleted when changing Python version.
| author | Joseph Myers <jsm@polyomino.org.uk> |
|---|---|
| date | Sun, 02 Sep 2018 23:48:04 +0000 |
| parents | 33a1f03b9de0 |
| children | 9ca128103a3a |
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==================== Implementation notes ==================== [see also the roundup package docstring] There have been some modifications to the spec. I've marked these in the source with 'XXX' comments when I remember to. In short: Class.find() - may match multiple properties, uses keyword args. Class.filter() - isn't in the spec and it's very useful to have at the Class level. CGI interface index view specifier layout part - lose the '+' from the sorting arguments (it's a reserved URL character ;). Just made no prefix mean ascending and '-' prefix descending. ItemClass - renamed to IssueClass to better match it only having one hypderdb class "issue". Allowing > 1 hyperdb class breaks the "superseder" multilink (since it can only link to one thing, and we'd want bugs to link to support and vice-versa). template - the call="link()" is handled by special-case mechanisms in my top-level CGI handler. In a nutshell, the handler looks for a method on itself called 'index%s' or 'item%s' where %s is a class. Most items pass on to the templating mechanism, but the file class _always_ does downloading. It'll probably stay this way too... template - call="link(property)" may be used to link "the current item" (from an index) - the link text is the property specified. template - added functions that I found very useful: List, History and Submit. template - items must specify the message lists, history, etc. Having them by default was sometimes not wanted. template - index view determines its default columns from the template's ``tal:condition="request/show/<property>"`` directives. template - menu() and field() look awfully similar now .... ;) roundup_admin.py - the command-line tool has a lot more commands at its disposal ----------------- Back to `Table of Contents`_ .. _`Table of Contents`: index.html