use _get_handle to produce file handle

Author: minggli

pandas/tests/frame/test_to_csv.py

@@ -9,6 +9,7 @@
 import numpy as np
 
 from pandas.compat import (lmap, range, lrange, StringIO, u)
+from pandas.io.common import _get_handle
 import pandas.core.common as com
 from pandas.errors import ParserError
 from pandas import (DataFrame, Index, Series, MultiIndex, Timestamp,
@@ -935,17 +936,19 @@ def test_to_csv_compression(self, df, encoding, compression):
         with ensure_clean() as filename:
 
             df.to_csv(filename, compression=compression, encoding=encoding)
-
             # test the round trip - to_csv -> read_csv
             result = read_csv(filename, compression=compression,
                               index_col=0, encoding=encoding)
-
-            with open(filename, 'w') as fh:
-                df.to_csv(fh, compression=compression, encoding=encoding)
-
-            result_fh = read_csv(filename, compression=compression,
-                                 index_col=0, encoding=encoding)
             assert_frame_equal(df, result)
+
+            # test the round trip using file handle - to_csv -> read_csv
+            f, _handles = _get_handle(filename, 'w', compression=compression,
+                                      encoding=encoding)
+            with f:
+                df.to_csv(f, encoding=encoding)
+            result_fh = pd.read_csv(filename, compression=compression,
+                                    encoding=encoding, index_col=0,
+                                    squeeze=True)
             assert_frame_equal(df, result_fh)
 
             # explicitly make sure file is compressed

pandas/tests/series/test_io.py

@@ -11,6 +11,7 @@
 from pandas import Series, DataFrame
 
 from pandas.compat import StringIO, u
+from pandas.io.common import _get_handle
 from pandas.util.testing import (assert_series_equal, assert_almost_equal,
                                  assert_frame_equal, ensure_clean)
 import pandas.util.testing as tm
@@ -151,19 +152,19 @@ def test_to_csv_compression(self, s, encoding, compression):
 
             s.to_csv(filename, compression=compression, encoding=encoding,
                      header=True)
-
             # test the round trip - to_csv -> read_csv
             result = pd.read_csv(filename, compression=compression,
                                  encoding=encoding, index_col=0, squeeze=True)
+            assert_series_equal(s, result)
 
-            with open(filename, 'w') as fh:
-                s.to_csv(fh, compression=compression, encoding=encoding,
-                         header=True)
-
+            # test the round trip using file handle - to_csv -> read_csv
+            f, _handles = _get_handle(filename, 'w', compression=compression,
+                                      encoding=encoding)
+            with f:
+                s.to_csv(f, encoding=encoding, header=True)
             result_fh = pd.read_csv(filename, compression=compression,
                                     encoding=encoding, index_col=0,
                                     squeeze=True)
-            assert_series_equal(s, result)
             assert_series_equal(s, result_fh)
 
             # explicitly ensure file was compressed