Add setting to customize the EXIF datetime format (fix #271)

- The default format is now `%c`
- Fix documentation confusion between ``datetime`` and ``dateobj``

docs/changelog.rst

@@ -15,6 +15,8 @@ Released on 2017-xx-xx.
 - Added random thumbnail property for album [:issue:`241`].
 - Improve CSP compatibility with colorbox theme [:issue:`245`].
 - Set html lang attribute based upon locale [:issue:`257`].
+- New setting ``datetime_format`` to customize the EXIF datetime format
+  [:issue:`271`].
 
 Version 1.3.0
 ~~~~~~~~~~~~~

docs/themes.rst

@@ -110,13 +110,18 @@ templates. If available, you can use:
     The aperture value given as an F-number and formatted as a decimal.
 
 ``media.exif.datetime``
+    The time the image was *taken*. It is formatted with the
+    ``datetime_format`` setting, which is ``%c`` by default.
+    See Python's `datetime documentation`_ for a list of all possible values.
+
+``media.exif.dateobj``
     The time the image was *taken*. It is a datetime object, that can be
     formatted with ``strftime``:
 
     .. code-block:: jinja
 
-        {% if media.exif.datetime %}
-            {{ media.exif.datetime.strftime('%A, %d. %B %Y') }}
+        {% if media.exif.dateobj %}
+            {{ media.exif.dateobj.strftime('%A, %d. %B %Y') }}
         {% endif %}
 
     This will output something like "Monday, 25. June 2013", depending on your
@@ -136,3 +141,5 @@ templates. If available, you can use:
             media.exif.gps.lat }}&lon={{ media.exif.long}}">Go to location</a>
         {% endif %}
 
+
+.. _datetime documentation: https://docs.python.org/3/library/datetime.html#strftime-strptime-behavior

sigal/gallery.py

@@ -159,7 +159,8 @@ class Image(Media):
 
     @cached_property
     def exif(self):
-        return (get_exif_tags(self.raw_exif)
+        datetime_format = self.settings['datetime_format']
+        return (get_exif_tags(self.raw_exif, datetime_format=datetime_format)
                 if self.raw_exif and self.ext in ('.jpg', '.jpeg') else None)
 
     @cached_property

sigal/image.py

@@ -243,7 +243,7 @@ def dms_to_degrees(v):
     return d + (m / 60.0) + (s / 3600.0)
 
 
-def get_exif_tags(data):
+def get_exif_tags(data, datetime_format='%c'):
     """Make a simplified version with common tags from raw EXIF data."""
 
     logger = logging.getLogger(__name__)
@@ -310,7 +310,7 @@ def get_exif_tags(data):
 
         try:
             simple['dateobj'] = datetime.strptime(date, '%Y:%m:%d %H:%M:%S')
-            dt = simple['dateobj'].strftime('%A, %d. %B %Y')
+            dt = simple['dateobj'].strftime(datetime_format)
             simple['datetime'] = dt.decode('utf8') if compat.PY2 else dt
         except (ValueError, TypeError) as e:
             logger.info(u'Could not parse DateTimeOriginal: %s', e)

sigal/settings.py

@@ -37,6 +37,7 @@ _DEFAULT_CONFIG = {
     'autorotate_images': True,
     'colorbox_column_size': 4,
     'copy_exif_data': False,
+    'datetime_format': '%c',
     'destination': '_build',
     'files_to_copy': (),
     'google_analytics': '',

sigal/templates/sigal.conf.py

@@ -69,6 +69,10 @@ img_size = (800, 600)
 # If True, EXIF data from the original image is copied to the resized image
 # copy_exif_data = False
 
+# Python's datetime format string used for the EXIF date formatting
+# https://docs.python.org/3/library/datetime.html#strftime-strptime-behavior
+# datetime_format = '%c'
+
 # Jpeg options
 # jpg_options = {'quality': 85,
 #                'optimize': True,

tests/test_gallery.py

@@ -113,9 +113,10 @@ def test_media_orig(settings, tmpdir):
 
 def test_image(settings, tmpdir):
     settings['destination'] = str(tmpdir)
+    settings['datetime_format'] = '%d/%m/%Y'
     m = Image('11.jpg', 'dir1/test1', settings)
     assert m.date == datetime.datetime(2006, 1, 22, 10, 32, 42)
-    assert m.exif['datetime'] == u'Sunday, 22. January 2006'
+    assert m.exif['datetime'] == u'22/01/2006'
 
     os.makedirs(join(settings['destination'], 'dir1', 'test1', 'thumbnails'))
     assert m.thumbnail == join('thumbnails', '11.tn.jpg')

tests/test_image.py

@@ -135,12 +135,12 @@ def test_get_exif_tags():
     src_file = os.path.join(CURRENT_DIR, 'sample', 'pictures', 'dir1', 'test1',
                             test_image)
     data = get_exif_data(src_file)
-    simple = get_exif_tags(data)
+    simple = get_exif_tags(data, datetime_format='%d/%m/%Y')
     assert simple['fstop'] == 3.9
     assert simple['focal'] == 12.0
     assert simple['iso'] == 50
     assert simple['Make'] == 'NIKON'
-    assert simple['datetime'] == 'Sunday, 22. January 2006'
+    assert simple['datetime'] == '22/01/2006'
     if PIL.PILLOW_VERSION == '3.0.0':
         assert simple['exposure'] == 0.00100603
     else: