fix pytest error

Author: charlesdong1991

pandas/tests/test_strings.py

@@ -924,14 +924,14 @@ def test_replace(self):
         tm.assert_almost_equal(rs, xp)
 
         # unicode
-        values = Series([u('fooBAD__barBAD'), NA])
+        values = Series([u'fooBAD__barBAD', NA])
 
         result = values.str.replace('BAD[_]*', '', regex=True)
-        exp = Series([u('foobar'), NA])
+        exp = Series([u'foobar', NA])
         tm.assert_series_equal(result, exp)
 
         result = values.str.replace('BAD[_]*', '', n=1, regex=True)
-        exp = Series([u('foobarBAD'), NA])
+        exp = Series([u'foobarBAD', NA])
         tm.assert_series_equal(result, exp)
 
         # flags + unicode
@@ -994,7 +994,7 @@ def test_replace_compiled_regex(self):
         exp = Series(['foobar', NA])
         tm.assert_series_equal(result, exp)
 
-        result = values.str.replace(pat, '', n=1)
+        result = values.str.replace(pat, '', n=1, regex=True)
         exp = Series(['foobarBAD', NA])
         tm.assert_series_equal(result, exp)
 
@@ -1008,14 +1008,14 @@ def test_replace_compiled_regex(self):
         tm.assert_almost_equal(rs, xp)
 
         # unicode
-        values = Series([u('fooBAD__barBAD'), NA])
+        values = Series([u'fooBAD__barBAD', NA])
 
         result = values.str.replace(pat, '', regex=True)
-        exp = Series([u('foobar'), NA])
+        exp = Series([u'foobar', NA])
         tm.assert_series_equal(result, exp)
 
         result = values.str.replace(pat, '', n=1, regex=True)
-        exp = Series([u('foobarBAD'), NA])
+        exp = Series([u'foobarBAD', NA])
         tm.assert_series_equal(result, exp)
 
         # flags + unicode