TST: Import abstract classes from collections.abc

Abstract collection classes accessed from the collections module
have been deprecated since Python 3.3. They should be
accessed through collections.abc. When run with Python
3.7, the deprecation warning cause multiple tests to
fail.

1 files changed, 7 insertions, 2 deletions

diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index 422a87322..07b845e2b 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -1,6 +1,11 @@
 from __future__ import division, absolute_import, print_function
 
-import collections
+try:
+    # Accessing collections abstact classes from collections
+    # has been deprecated since Python 3.3
+    import collections.abc as collections_abc
+except ImportError:
+    import collections as collections_abc
 import re
 import sys
 import warnings
@@ -547,7 +552,7 @@ def piecewise(x, condlist, funclist, *args, **kw):
     y = zeros(x.shape, x.dtype)
     for k in range(n):
         item = funclist[k]
-        if not isinstance(item, collections.Callable):
+        if not isinstance(item, collections_abc.Callable):
             y[condlist[k]] = item
         else:
             vals = x[condlist[k]]