Fix for Python 3.7

Author: erezsh

data_diff/utils.py

@@ -5,6 +5,7 @@
 from abc import ABC, abstractmethod
 from urllib.parse import urlparse
 from uuid import UUID
+import operator
 import string
 
 alphanums = string.digits + string.ascii_lowercase
@@ -221,3 +222,19 @@ def match_like(pattern: str, strs: Sequence[str]) -> Iterable[str]:
     for s in strs:
         if reo.match(s):
             yield s
+
+
+def accumulate(iterable, func=operator.add, *, initial=None):
+    'Return running totals'
+    # Taken from https://docs.python.org/3/library/itertools.html#itertools.accumulate, to backport 'initial' to 3.7
+    it = iter(iterable)
+    total = initial
+    if initial is None:
+        try:
+            total = next(it)
+        except StopIteration:
+            return
+    yield total
+    for element in it:
+        total = func(total, element)
+        yield total

tests/test_database_types.py

@@ -8,13 +8,13 @@
 from datetime import datetime, timedelta, timezone
 import logging
 from decimal import Decimal
-from itertools import islice, accumulate, repeat, chain
+from itertools import islice, repeat, chain
 
 from parameterized import parameterized
 
 from data_diff import databases as db
 from data_diff.databases import postgresql, oracle
-from data_diff.utils import number_to_human
+from data_diff.utils import number_to_human, accumulate
 from data_diff.diff_tables import TableDiffer, TableSegment, DEFAULT_BISECTION_THRESHOLD
 from .common import (
     CONN_STRINGS,