diff --git a/sumpy/tools.py b/sumpy/tools.py index 863b4bb91749adef6ea65a374d697ecfa8d30bc4..540208f342e429326b7571168b754f02c0041d79 100644 --- a/sumpy/tools.py +++ b/sumpy/tools.py @@ -559,10 +559,13 @@ class MatrixBlockIndexRanges(object): # Author: Raymond Hettinger # License: MIT -import collections +try: + from collections.abc import MutableSet +except ImportError: + from collections import MutableSet -class OrderedSet(collections.MutableSet): +class OrderedSet(MutableSet): def __init__(self, iterable=None): self.end = end = []