replace ChainPredicate class with 'functools.partial'

gallery_dl/util.py

@@ -403,8 +403,14 @@ def build_predicate(predicates):
         return lambda url, kwdict: True
     elif len(predicates) == 1:
         return predicates[0]
-    else:
-        return ChainPredicate(predicates)
+    return functools.partial(chain_predicates, predicates)
+
+
+def chain_predicates(predicates, url, kwdict):
+    for pred in predicates:
+        if not pred(url, kwdict):
+            return False
+    return True
 
 
 class RangePredicate():
@@ -508,18 +514,6 @@ class FilterPredicate():
             raise exception.FilterError(exc)
 
 
-class ChainPredicate():
-    """Predicate; True if all of its predicates return True"""
-    def __init__(self, predicates):
-        self.predicates = predicates
-
-    def __call__(self, url, kwdict):
-        for pred in self.predicates:
-            if not pred(url, kwdict):
-                return False
-        return True
-
-
 class ExtendedUrl():
     """URL with attached config key-value pairs"""
     def __init__(self, url, gconf, lconf):

test/test_util.py

@@ -124,7 +124,7 @@ class TestPredicate(unittest.TestCase):
 
         pred = util.build_predicate([util.UniquePredicate(),
                                      util.UniquePredicate()])
-        self.assertIsInstance(pred, util.ChainPredicate)
+        self.assertIs(pred.func, util.chain_predicates)
 
 
 class TestISO639_1(unittest.TestCase):