Fix parsing of lists with relativedelta objects.

The relativedelta objects were rejected because we cannot compare them to
strings. Both `==` and `!=` results to `False`.

Instead we have to first test the type and then do the comparison.

pyhocon/config_parser.py

@@ -63,6 +63,13 @@ def glob(pathname, recursive=False):
 else:
     from glob import glob
 
+
+try:
+    from dateutil.relativedelta import relativedelta as period_impl
+except Exception:
+    from datetime import timedelta as period_impl
+
+
 logger = logging.getLogger(__name__)
 
 #
@@ -87,11 +94,6 @@ class STR_SUBSTITUTION(object):
 
 
 def period(period_value, period_unit):
-    try:
-        from dateutil.relativedelta import relativedelta as period_impl
-    except Exception:
-        from datetime import timedelta as period_impl
-
     if period_unit == 'nanoseconds':
         period_unit = 'microseconds'
         period_value = int(period_value / 1000)
@@ -749,9 +751,26 @@ def postParse(self, instring, loc, token_list):
         :param token_list:
         :return:
         """
-        cleaned_token_list = [token for tokens in (token.tokens if isinstance(token, ConfigInclude) else [token]
-                                                   for token in token_list if token != '')
-                              for token in tokens]
+        cleaned_token_list = []
+
+        # Note that:
+        # relativedelta.__eq__() raises NotImplemented if it is compared with
+        # a different object type so Python falls back to identity comparison.
+        # We cannot compare this object to a string.
+        # >>> relativedelta(hours = 1) == ''
+        # False
+        # >>> relativedelta(hours = 1) != ''
+        # False
+        for token in token_list:
+            # This is the case when there was a trailing comma in the list.
+            # The last token is just an empty string.
+            if isinstance(token, str) and token == '':
+                continue
+            if isinstance(token, ConfigInclude):
+                cleaned_token_list.extend(token.tokens)
+            else:
+                cleaned_token_list.append(token)
+
         config_list = ConfigList(cleaned_token_list)
         return [config_list]
 

tests/test_config_parser.py

@@ -148,6 +148,16 @@ def test_parse_string_with_duration_with_long_unit_name(self):
         )
         assert config['b'] == period(weeks=10)
 
+    def test_parse_with_list_mixed_types_with_durations_and_trailing_comma(self):
+        config = ConfigFactory.parse_string(
+            """
+            a: foo
+            b: [a, 1, 10 weeks, 5 minutes,]
+            c: bar
+            """
+        )
+        assert config['b'] == ['a', 1, period(weeks=10), period(minutes=5)]
+
     def test_parse_with_enclosing_square_bracket(self):
         config = ConfigFactory.parse_string("[1, 2, 3]")
         assert config == [1, 2, 3]