Simply and improve read_csv_infer_compression test

Author: Evan Wright

pandas/io/tests/test_parsers.py

@@ -1072,17 +1072,16 @@ def test_read_csv_no_index_name(self):
         tm.assert_frame_equal(df, df2)
 
     def test_read_csv_infer_compression(self):
+        expected = self.read_csv(self.csv1, index_col=0, parse_dates=True)
+
         inputs = [self.csv1, self.csv1 + '.gz',
                   self.csv1 + '.bz2', open(self.csv1)]
 
         for f in inputs:
             df = self.read_csv(f, index_col=0, parse_dates=True,
                 compression='infer')
 
-            self.assert_numpy_array_equal(df.columns, ['A', 'B', 'C', 'D'])
-            self.assertEqual(df.index.name, 'index')
-            self.assertIsInstance(df.index[0], (datetime, np.datetime64, Timestamp))
-            self.assertEqual(df.values.dtype, np.float64)
+            tm.assert_frame_equal(expected, df)
 
         inputs[3].close()