img: add Image.load()

Steve Canny · Steve Canny · commit fe8a48974c2a · 2013-12-28T02:34:31.000-08:00
diff --git a/docx/parts/image.py b/docx/parts/image.py
@@ -6,26 +6,54 @@
 
 from __future__ import absolute_import, print_function, unicode_literals
 
+import hashlib
+import os
+
 from docx.opc.package import Part
+from docx.shared import lazyproperty
 
 
 class Image(object):
     """
     A helper object that knows how to analyze an image file.
     """
+    def __init__(self, blob, filename):
+        super(Image, self).__init__()
+        self._blob = blob
+        self._filename = filename
+
+    @property
+    def filename(self):
+        """
+        Original image file name, if loaded from disk, or a generic filename
+        if loaded from an anonymous stream.
+        """
+        return self._filename
+
     @classmethod
-    def load(self, image_descriptor):
+    def load(cls, image_descriptor):
         """
         Return a new |Image| instance loaded from the image file identified
         by *image_descriptor*, a path or file-like object.
         """
+        if isinstance(image_descriptor, basestring):
+            path = image_descriptor
+            with open(path, 'rb') as f:
+                blob = f.read()
+            filename = os.path.basename(path)
+        else:
+            stream = image_descriptor
+            stream.seek(0)
+            blob = stream.read()
+            filename = None
+        return cls(blob, filename)
 
-    @property
+    @lazyproperty
     def sha1(self):
         """
         SHA1 hash digest of the image blob
         """
-        raise NotImplementedError
+        return hashlib.sha1(self._blob).hexdigest()
 
 
 class ImagePart(Part):
diff --git a/tests/parts/test_image.py b/tests/parts/test_image.py
@@ -0,0 +1,29 @@
+# encoding: utf-8
+
+"""
+Test suite for docx.parts.image module
+"""
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+from docx.parts.image import Image
+
+from ..unitutil import test_file
+
+
+class DescribeImage(object):
+
+    def it_can_construct_from_an_image_path(self):
+        image_file_path = test_file('monty-truth.png')
+        image = Image.load(image_file_path)
+        assert isinstance(image, Image)
+        assert image.sha1 == '79769f1e202add2e963158b532e36c2c0f76a70c'
+        assert image.filename == 'monty-truth.png'
+
+    def it_can_construct_from_an_image_stream(self):
+        image_file_path = test_file('monty-truth.png')
+        with open(image_file_path, 'rb') as image_file_stream:
+            image = Image.load(image_file_stream)
+        assert isinstance(image, Image)
+        assert image.sha1 == '79769f1e202add2e963158b532e36c2c0f76a70c'
+        assert image.filename is None
diff --git a/tests/unitutil.py b/tests/unitutil.py
@@ -35,6 +35,13 @@ def docx_path(name):
     return absjoin(_thisdir, 'test_files', '%s.docx' % name)
 
 
+def test_file(name):
+    """
+    Return the absolute path to test file having *name*.
+    """
+    return absjoin(_thisdir, 'test_files', name)
+
+
 # ===========================================================================
 # pytest mocking helpers
 # ===========================================================================
diff --git a/tox.ini b/tox.ini
@@ -9,9 +9,10 @@
 # Configuration for tox and pytest
 
 [pytest]
-norecursedirs = doc docx *.egg-info features .git .tox
+norecursedirs = doc docx *.egg-info features .git ref _scratch .tox
+python_files = test_*.py
 python_classes = Test Describe
-python_functions = test_ it_ they_
+python_functions = it_ they_
 
 [tox]
 envlist = py26, py27, py33
