Create normalize_topic_list function

web3/utils/events.py

@@ -221,3 +221,21 @@ def get_event_data(event_abi, log_entry):
     }
 
     return AttributeDict.recursive(event_data)
+
+
+@to_tuple
+def pop_singlets(seq):
+    yield from (i[0] if is_list_like(i) and len(i) == 1 else i for i in seq)
+
+
+@curry
+def remove_trailing_from_seq(seq, remove_value=None):
+    index = len(seq)
+    while index > 0 and seq[index - 1] == remove_value:
+        index -= 1
+    return seq[:index]
+
+
+normalize_topic_list = compose(
+    remove_trailing_from_seq(remove_value=None),
+    pop_singlets,)