DOC/TST: core/generic/drop doc-string and tests

Author: jreback

pandas/core/generic.py

@@ -1092,7 +1092,7 @@ def drop(self, labels, axis=0, level=None):
 
         Parameters
         ----------
-        labels : list-like
+        labels : list-like; passing a string or tuple will be treated as a single index label
         axis : int
         level : int or name, default None
             For MultiIndex

pandas/tests/test_series.py

@@ -1440,6 +1440,11 @@ def test_drop(self):
         result = s.drop('one')
         assert_series_equal(result,expected)
 
+        # single string/tuple-like
+        s = Series(range(3),index=list('abc'))
+        self.assertRaises(ValueError, s.drop, 'bc')
+        self.assertRaises(ValueError, s.drop, ('a',))
+
     def test_ix_setitem(self):
         inds = self.series.index[[3, 4, 7]]