Improve error handling and fix a bug in is_list utility function

dtags/commands/tags.py

@@ -72,6 +72,8 @@ def main():
     parsed = parser.parse_args()
 
     if parsed.edit:
+        if parsed.search_terms:
+            raise parser.error('no arguments allowed with option -e/--edit')
         edit_file_path = TAGS_FILE_PATH + '.edit'
         shutil.copy2(TAGS_FILE_PATH, edit_file_path)
         subprocess.call([os.environ.get('EDITOR', 'vi'), edit_file_path])

dtags/config.py

@@ -102,4 +102,6 @@ def check_tags(tags):
             raise ValueError('expecting a non-empty list for {}'.format(tag))
         for path in paths:
             if not (is_str(path) and os.path.isdir(expand_path(path))):
-                raise ValueError('invalid directory path for {}'.format(tag))
+                raise ValueError(
+                    'invalid directory path {} for {}'.format(path, tag)
+                )

dtags/utils.py

@@ -6,7 +6,7 @@
 import importlib
 from sys import stderr
 
-from collections import Mapping, Iterable
+from collections import Mapping
 # Importing this way for python 2 and 3 compatibility
 try:
     urllib = importlib.import_module('urllib.parse')
@@ -34,7 +34,7 @@ def is_list(obj):
     :param obj: object to check
     :return: True if iterable, else False
     """
-    return isinstance(obj, Iterable)
+    return type(obj) == list
 
 
 def is_dict(obj):