Fixing silly error in tests

Author: AaronCritchley

pandas/tests/io/parser/usecols.py

@@ -492,11 +492,11 @@ def test_raise_on_usecols_names_mismatch(self):
         tm.assert_frame_equal(df, expected)
 
         usecols = ['a', 'b', 'c', 'f']
-        with tm.assert_raises_regex(ValueError, msg.format(missing=['f'])):
+        with tm.assert_raises_regex(ValueError, msg.format(missing="\['f'\]")):
             self.read_csv(StringIO(data), usecols=usecols)
 
         usecols = ['a', 'b', 'f']
-        with tm.assert_raises_regex(ValueError, msg.format(missing=['f'])):
+        with tm.assert_raises_regex(ValueError, msg.format(missing="\['f'\]")):
             self.read_csv(StringIO(data), usecols=usecols)
 
         names = ['A', 'B', 'C', 'D']
@@ -520,9 +520,9 @@ def test_raise_on_usecols_names_mismatch(self):
         # tm.assert_frame_equal(df, expected)
 
         usecols = ['A', 'B', 'C', 'f']
-        with tm.assert_ra(ValueError, msg.format(missing=['f'])):
+        with tm.assert_raises_regex(ValueError, msg.format(missing="\['f'\]")):
             self.read_csv(StringIO(data), header=0, names=names,
                           usecols=usecols)
         usecols = ['A', 'B', 'f']
-        with tm.assert_raises_regex(ValueError, msg.format(missing=['f'])):
+        with tm.assert_raises_regex(ValueError, msg.format(missing="\['f'\]")):
             self.read_csv(StringIO(data), names=names, usecols=usecols)