Add invalid compression test

Author: dhimmel

pandas/io/parsers.py

@@ -385,7 +385,8 @@ def _read(filepath_or_buffer, kwds):
 
     compression = kwds.get('compression')
     if compression not in set(_compression_to_extension) | {None, 'infer'}:
-        raise ValueError('"{}" is not a valid compression'.format(compression))
+        msg = 'Unrecognized compression type: {}'.format(compression)
+        raise ValueError(msg)
 
     if compression == 'infer':
         compression = _infer_compression(filepath_or_buffer)

pandas/io/tests/parser/compression.py

@@ -168,3 +168,8 @@ def test_read_csv_infer_compression(self):
             tm.assert_frame_equal(expected, df)
 
         inputs[3].close()
+
+    def test_invalid_compression(self):
+        msg = 'Unrecognized compression type: sfark'
+        with tm.assertRaisesRegexp(ValueError, msg):
+            self.read_csv('test_file.zip', compression='sfark')