Add can_parse class method to MediaInfo, fixes #34

pymediainfo/__init__.py

@@ -66,17 +66,26 @@ def parse_xml_data_into_dom(xml_data):
         except:
             return None
     @staticmethod
-    def parse(filename):
+    def _get_library():
         if os.name in ("nt", "dos", "os2", "ce"):
-            lib = windll.MediaInfo
+            return windll.MediaInfo
         elif sys.platform == "darwin":
             try:
-                lib = CDLL("libmediainfo.0.dylib")
+                return CDLL("libmediainfo.0.dylib")
             except OSError:
-                lib = CDLL("libmediainfo.dylib")
+                return CDLL("libmediainfo.dylib")
         else:
-            lib = CDLL("libmediainfo.so.0")
-
+            return CDLL("libmediainfo.so.0")
+    @classmethod
+    def can_parse(cls):
+        try:
+            cls._get_library()
+            return True
+        except:
+            return False
+    @classmethod
+    def parse(cls, filename):
+        lib = cls._get_library()
         # Test file is readable
         with open(filename, "rb"):
             pass
@@ -110,7 +119,7 @@ def parse(filename):
         # Delete the handle
         lib.MediaInfo_Close(handle)
         lib.MediaInfo_Delete(handle)
-        return MediaInfo(xml)
+        return cls(xml)
     def _populate_tracks(self):
         if self.xml_dom is None:
             return

tests/test.py

@@ -50,6 +50,8 @@ def test_parse_invalid_xml(self):
 class MediaInfoLibraryTest(unittest.TestCase):
     def setUp(self):
         self.mi = MediaInfo.parse(os.path.join(data_dir, "sample.mp4"))
+    def test_can_parse_true(self):
+        self.assertTrue(MediaInfo.can_parse())
     def test_track_count(self):
         self.assertEqual(len(self.mi.tracks), 3)
     def test_track_types(self):