fr

Author: h-vetinari

pandas/core/frame.py

@@ -3888,25 +3888,25 @@ def set_index(self, keys, drop=True, append=False, inplace=False,
         3  2013  7      84
         4  2014  10     31
         """
-        from pandas import Series
-
         if not isinstance(keys, list):
             keys = [keys]
 
-        # collect elements from "keys" that are not allowed array types
-        col_labels = [x for x in keys
-                      if not isinstance(x, (Series, Index, MultiIndex,
-                                            list, np.ndarray))]
-        if any(x not in self for x in col_labels):
-            # if there are any labels that are invalid, we raise a KeyError
-            missing = [x for x in col_labels if x not in self]
+        missing = []
+        for x in keys:
+            if not (is_scalar(x) or isinstance(x, tuple)):
+                if not isinstance(x, (ABCSeries, ABCIndexClass, ABCMultiIndex,
+                                      list, np.ndarray)):
+                    raise TypeError('keys may only contain a combination of '
+                                    'the following: valid column keys, '
+                                    'Series, Index, MultiIndex, list or '
+                                    'np.ndarray')
+            else:
+                if x not in self:
+                    missing.append(x)
+
+        if missing:
             raise KeyError('{}'.format(missing))
-        elif len(set(col_labels)) < len(col_labels):
-            # if all are valid labels, but there are duplicates
-            dup = Series(col_labels)
-            dup = list(dup.loc[dup.duplicated()])
-            raise ValueError('Passed duplicate column names '
-                             'to keys: {dup}'.format(dup=dup))
+
         vi = verify_integrity
         return super(DataFrame, self).set_index(keys=keys, drop=drop,
                                                 append=append, inplace=inplace,