Use not is_list_like

Author: Dr-Irv

doc/source/whatsnew/v0.20.0.txt

@@ -351,7 +351,7 @@ Bug Fixes
 - Bug in converting object elements of array-like objects to unsigned 64-bit integers (:issue:`4471`, :issue:`14982`)
 - Bug in ``pd.pivot_table()`` where no error was raised when values argument was not in the columns (:issue:`14938`)
 
-- Bug in ``DataFrame.groupby().describe()`` when grouping on  ``Index`` containing tuples (:issue:`14848`)
+- Bug in ``DataFrame.groupby().describe()`` when grouping on ``Index`` containing tuples. Raise `ValueError` if creating an `Index` with tuples and not passing a list of names (:issue:`14848`)
 
 
 

pandas/indexes/multi.py

@@ -20,7 +20,6 @@
                                  is_object_dtype,
                                  is_iterator,
                                  is_list_like,
-                                 is_string_like,
                                  is_scalar)
 from pandas.types.missing import isnull, array_equivalent
 from pandas.core.common import (_values_from_object,
@@ -493,9 +492,8 @@ def _set_names(self, names, level=None, validate=True):
 
         # GH 15110
         # Don't allow a single string for names in a MultiIndex
-        if names is not None and is_string_like(names):
-            raise ValueError('Names should not be a single string for a '
-                             'MultiIndex.')
+        if names is not None and not is_list_like(names):
+            raise ValueError('Names should be list-like for a MultiIndex')
         names = list(names)
 
         if validate and level is not None and len(names) != len(level):