Revert fix for 22722

Author: h-vetinari

pandas/core/strings.py

@@ -2118,13 +2118,6 @@ def cat(self, others=None, sep=None, na_rep=None, join=None):
                                  'must all be of the same length as the '
                                  'calling Series/Index.')
 
-        if any(not is_object_dtype(x)
-               and not (is_categorical_dtype(x)
-                        and is_object_dtype(x.cat.categories))
-               for x in others):
-            raise TypeError('All columns in others must contain only strings '
-                            '(or missing values)!')
-
         if join is None and warn:
             warnings.warn("A future version of pandas will perform index "
                           "alignment when `others` is a Series/Index/"

pandas/tests/test_strings.py

@@ -195,13 +195,6 @@ def test_str_cat_categorical(self, box, dtype_caller, dtype_target):
             result = s.str.cat(t)
             assert_series_or_index_equal(result, expected)
 
-        # errors for inputs not consisting of strings (also when categorical)
-        rgx = 'All columns in others must contain only strings.*'
-
-        # data with non-object dtype
-        with tm.assert_raises_regex(TypeError, rgx):
-            s.str.cat(Series([1, 2, 3, 4]))
-
     @pytest.mark.parametrize('box', [Series, Index])
     def test_str_cat_mixed_inputs(self, box):
         s = Index(['a', 'b', 'c', 'd'])
@@ -312,13 +305,6 @@ def test_str_cat_mixed_inputs(self, box):
         with tm.assert_raises_regex(TypeError, rgx):
             s.str.cat(1)
 
-        # errors for inputs not consisting of strings
-        rgx = 'All columns in others must contain only strings.*'
-
-        # data with non-object dtype
-        with tm.assert_raises_regex(TypeError, rgx):
-            s.str.cat(Series([1, 2, 3, 4]))
-
     @pytest.mark.parametrize('join', ['left', 'outer', 'inner', 'right'])
     @pytest.mark.parametrize('box', [Series, Index])
     def test_str_cat_align_indexed(self, box, join):