FIX isfileobj accepts write-mode files under PY3

1 files changed, 19 insertions, 0 deletions

diff --git a/numpy/compat/tests/test_compat.py b/numpy/compat/tests/test_compat.py
new file mode 100644
index 000000000..3df142e04
--- /dev/null
+++ b/numpy/compat/tests/test_compat.py
@@ -0,0 +1,19 @@
+from os.path import join
+
+from numpy.compat import isfileobj
+from numpy.testing import TestCase, assert_
+from numpy.testing.utils import tempdir
+
+
+def test_isfileobj():
+    with tempdir(prefix="numpy_test_compat_") as folder:
+        filename = join(folder, 'a.bin')
+
+        with open(filename, 'wb') as f:
+            assert_(isfileobj(f))
+
+        with open(filename, 'ab') as f:
+            assert_(isfileobj(f))
+
+        with open(filename, 'rb') as f:
+            assert_(isfileobj(f))