Changed get_system_library_path to return None if could not get system library

README.md

@@ -692,7 +692,7 @@ The following functions are located in osxphotos.utils
 
 #### ```get_system_library_path()```
 
-**MacOS 10.15 Only** Returns path to System Photo Library as string.  On MacOS version < 10.15, raises Exception.
+**MacOS 10.15 Only** Returns path to System Photo Library as string.  On MacOS version < 10.15, returns None.
 
 #### ```get_last_library_path()```
 

osxphotos/utils.py

@@ -169,12 +169,13 @@ def dd_to_dms_str(lat, lon):
 def get_system_library_path():
     """ return the path to the system Photos library as string """
     """ only works on MacOS 10.15+ """
-    """ on earlier versions, will raise exception """
+    """ on earlier versions, returns None """
     _, major, _ = _get_os_version()
     if int(major) < 15:
-        raise Exception(
-            "get_system_library_path not implemented for MacOS < 10.15", major
+        logging.debug(
+            f"get_system_library_path not implemented for MacOS < 10.15: you have {major}"
         )
+        return None
 
     plist_file = Path(
         str(Path.home())

tests/test_utils.py

@@ -31,8 +31,7 @@ def test_get_system_library_path():
 
     _, major, _ = osxphotos.utils._get_os_version()
     if int(major) < 15:
-        with pytest.raises(Exception):
-            assert osxphotos.utils.get_system_library_path()
+        assert osxphotos.utils.get_system_library_path() is None
     else:
         assert osxphotos.utils.get_system_library_path() is not None