frame: exclude string from Iterable in constructor

Author: holymonson

pandas/core/frame.py

@@ -74,7 +74,8 @@
 from pandas.core.arrays import Categorical, ExtensionArray
 import pandas.core.algorithms as algorithms
 from pandas.compat import (range, map, zip, lrange, lmap, lzip, StringIO, u,
-                           OrderedDict, raise_with_traceback)
+                           OrderedDict, raise_with_traceback,
+                           string_and_binary_types)
 from pandas import compat
 from pandas.compat import PY36
 from pandas.compat.numpy import function as nv
@@ -389,7 +390,8 @@ def __init__(self, data=None, index=None, columns=None, dtype=None,
             else:
                 mgr = self._init_ndarray(data, index, columns, dtype=dtype,
                                          copy=copy)
-        elif isinstance(data, collections.Iterable):
+        elif (isinstance(data, collections.Iterable)
+              and not isinstance(data, string_and_binary_types)):
             if not isinstance(data, collections.Sequence):
                 data = list(data)
             if len(data) > 0:

pandas/tests/series/test_constructors.py

@@ -166,6 +166,12 @@ def __iter__(self):
         result = Series(Iter(), dtype='int64')
         assert_series_equal(result, expected)
 
+    def test_constructor_single_str(self):
+
+        expected = Series(['abc'])
+        result = Series('abc')
+        assert_series_equal(result, expected)
+
     def test_constructor_list_like(self):
 
         # make sure that we are coercing different