Fixture for mock

Author: TomAugspurger

pandas/conftest.py

@@ -1,3 +1,5 @@
+import importlib
+
 import pytest
 
 import numpy as np
@@ -249,3 +251,17 @@ def any_int_dtype(request):
     """
 
     return request.param
+
+
+@pytest.fixture
+def mock():
+    """
+    Fixture providing the 'mock' module.
+
+    Uses 'unittest.mock' for Python 3. Attempts to import the 3rd party 'mock'
+    package for Python 2, skipping if not present.
+    """
+    if PY3:
+        return importlib.import_module("unittest.mock")
+    else:
+        return pytest.importorskip("mock")

pandas/tests/dtypes/test_inference.py

@@ -128,7 +128,7 @@ def test_is_dict_like_fails(ll):
     assert not inference.is_dict_like(ll)
 
 
-def test_is_file_like():
+def test_is_file_like(mock):
     class MockFile(object):
         pass
 
@@ -166,10 +166,7 @@ class MockFile(object):
     # Iterator but no read / write attributes
     data = [1, 2, 3]
     assert not is_file(data)
-
-    if PY3:
-        from unittest import mock
-        assert not is_file(mock.Mock())
+    assert not is_file(mock.Mock())
 
 
 @pytest.mark.parametrize(

pandas/tests/io/parser/common.py

@@ -1546,7 +1546,7 @@ def test_file_handles(self):
                     assert not m.closed
                 m.close()
 
-    def test_invalid_file_buffer(self):
+    def test_invalid_file_buffer(self, mock):
         # see gh-15337
 
         class InvalidBuffer(object):
@@ -1577,11 +1577,8 @@ def seek(self, pos, whence=0):
 
         tm.assert_frame_equal(result, expected)
 
-        if PY3:
-            from unittest import mock
-
-            with tm.assert_raises_regex(ValueError, msg):
-                self.read_csv(mock.Mock())
+        with tm.assert_raises_regex(ValueError, msg):
+            self.read_csv(mock.Mock())
 
     @tm.capture_stderr
     def test_skip_bad_lines(self):

pandas/tests/io/test_gcs.py

@@ -8,27 +8,17 @@
 from pandas.util.testing import assert_frame_equal
 
 
-@pytest.fixture
-def mock_patch():
-    try:
-        from unittest.mock import patch
-    except ImportError:
-        from mock import patch
-
-    return patch
-
-
 def test_is_gcs_url():
     assert is_gcs_url("gcs://pandas/somethingelse.com")
     assert is_gcs_url("gs://pandas/somethingelse.com")
     assert not is_gcs_url("s3://pandas/somethingelse.com")
 
 
 @td.skip_if_no('gcsfs')
-def test_read_csv_gcs(mock_patch):
+def test_read_csv_gcs(mock):
     df1 = DataFrame({'int': [1, 3], 'float': [2.0, np.nan], 'str': ['t', 's'],
                      'dt': date_range('2018-06-18', periods=2)})
-    with mock_patch('gcsfs.GCSFileSystem') as MockFileSystem:
+    with mock.patch('gcsfs.GCSFileSystem') as MockFileSystem:
         instance = MockFileSystem.return_value
         instance.open.return_value = StringIO(df1.to_csv(index=False))
         df2 = read_csv('gs://test/test.csv', parse_dates=['dt'])
@@ -37,10 +27,10 @@ def test_read_csv_gcs(mock_patch):
 
 
 @td.skip_if_no('gcsfs')
-def test_gcs_get_filepath_or_buffer(mock_patch):
+def test_gcs_get_filepath_or_buffer(mock):
     df1 = DataFrame({'int': [1, 3], 'float': [2.0, np.nan], 'str': ['t', 's'],
                      'dt': date_range('2018-06-18', periods=2)})
-    with mock_patch('pandas.io.gcs.get_filepath_or_buffer') as MockGetFilepath:
+    with mock.patch('pandas.io.gcs.get_filepath_or_buffer') as MockGetFilepath:
         MockGetFilepath.return_value = (StringIO(df1.to_csv(index=False)),
                                         None, None, False)
         df2 = read_csv('gs://test/test.csv', parse_dates=['dt'])