Move iptc field extraction to image.py

sigal/gallery.py

@@ -170,19 +170,16 @@ class Image(Media):
     def _get_metadata(self):
         super(Image, self)._get_metadata()
         # If a title or description hasn't been obtained by other means, look
-        #  for the information in IPTC fields as catalogued in:
-        # https://www.iptc.org/std/photometadata/specification/IPTC-PhotoMetadata
-        if not self.title or not self.description:
-            iptc_data = get_iptc_data(self.src_path)
-            if iptc_data and not self.title:
-                # 2:05 is the IPTC title property
-                if (2, 5) in iptc_data:
-                    self.title = iptc_data[(2, 5)].decode('utf-8')
+        #  for the information in IPTC fields
+        if self.title and self.description:
+            # Nothing to do - we already have title and description
+            return
 
-            if iptc_data and not self.description:
-                # 2:120 is the IPTC description property
-                if (2, 120) in iptc_data:
-                    self.description = iptc_data[(2, 120)].decode('utf-8')
+        iptc_data = get_iptc_data(self.src_path)
+        if not self.title and iptc_data.get('title'):
+            self.title = iptc_data['title']
+        if not self.description and iptc_data.get('description'):
+            self.description = iptc_data['description']
 
     @cached_property
     def raw_exif(self):

sigal/image.py

@@ -241,7 +241,19 @@ def get_iptc_data(filename):
     """Return a dict with the raw IPTC data."""
 
     img = _read_image(filename)
-    return IptcImagePlugin.getiptcinfo(img)
+    raw_iptc = IptcImagePlugin.getiptcinfo(img)
+    # IPTC fields are catalogued in:
+    # https://www.iptc.org/std/photometadata/specification/IPTC-PhotoMetadata
+    iptc_data = {}
+    # 2:05 is the IPTC title property
+    if raw_iptc and (2, 5) in raw_iptc:
+        iptc_data["title"] = raw_iptc[(2, 5)].decode('utf-8')
+
+    # 2:120 is the IPTC description property
+    if raw_iptc and (2, 120) in raw_iptc:
+        iptc_data["description"] = raw_iptc[(2, 120)].decode('utf-8')
+
+    return iptc_data
 
 
 def dms_to_degrees(v):

tests/test_image.py

@@ -168,19 +168,19 @@ def test_get_iptc_data():
                             test_image)
     data = get_iptc_data(src_file)
     # Title
-    assert data[(2, 5)] == b'Haemostratulus clouds over Canberra - ' + \
-            b'2005-12-28 at 03-25-07'
+    assert data["title"] == 'Haemostratulus clouds over Canberra - ' + \
+            '2005-12-28 at 03-25-07'
     # Description
-    assert data[(2, 120)] == b'"Haemo" because they look like haemoglobin ' + \
-            b'cells and "stratulus" because I can\'t work out whether ' + \
-            b'they\'re Stratus or Cumulus clouds.\nWe\'re driving down ' + \
-            b'the main drag in Canberra so it\'s Parliament House that ' + \
-            b'you can see at the end of the road.'
+    assert data["description"] == '"Haemo" because they look like haemoglobin ' + \
+            'cells and "stratulus" because I can\'t work out whether ' + \
+            'they\'re Stratus or Cumulus clouds.\nWe\'re driving down ' + \
+            'the main drag in Canberra so it\'s Parliament House that ' + \
+            'you can see at the end of the road.'
     # This file has no IPTC data
     test_image = '21.jpg'
     src_file = os.path.join(CURRENT_DIR, 'sample', 'pictures', 'exifTest',
                             test_image)
-    assert get_iptc_data(src_file) is None
+    assert get_iptc_data(src_file) == {}
 
 
 def test_iso_speed_ratings():