allow using Iterable in Series and DataFrame constructor

Author: holymonson

pandas/core/frame.py

@@ -16,7 +16,6 @@
 import collections
 import itertools
 import sys
-import types
 import warnings
 from textwrap import dedent
 
@@ -390,8 +389,8 @@ 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, (list, types.GeneratorType)):
-            if isinstance(data, types.GeneratorType):
+        elif isinstance(data, collections.Iterable):
+            if not isinstance(data, collections.Sequence):
                 data = list(data)
             if len(data) > 0:
                 if is_list_like(data[0]) and getattr(data[0], 'ndim', 1) == 1:
@@ -416,8 +415,6 @@ def __init__(self, data=None, index=None, columns=None, dtype=None,
                                              copy=copy)
             else:
                 mgr = self._init_dict({}, index, columns, dtype=dtype)
-        elif isinstance(data, collections.Iterator):
-            raise TypeError("data argument can't be an iterator")
         else:
             try:
                 arr = np.array(data, dtype=dtype, copy=copy)

pandas/core/series.py

@@ -6,7 +6,7 @@
 # pylint: disable=E1101,E1103
 # pylint: disable=W0703,W0622,W0613,W0201
 
-import types
+import collections
 import warnings
 from textwrap import dedent
 
@@ -242,13 +242,12 @@ def __init__(self, data=None, index=None, dtype=None, name=None,
                                      "extension array of a different "
                                      "dtype ('{}').".format(dtype,
                                                             data.dtype))
-
-            elif (isinstance(data, types.GeneratorType) or
-                  (compat.PY3 and isinstance(data, map))):
-                data = list(data)
             elif isinstance(data, (set, frozenset)):
                 raise TypeError("{0!r} type is unordered"
                                 "".format(data.__class__.__name__))
+            elif (isinstance(data, collections.Iterable)
+                  and not isinstance(data, collections.Sized)):
+                data = list(data)
             else:
 
                 # handle sparse passed here (and force conversion)

pandas/tests/frame/test_constructors.py

@@ -953,6 +953,16 @@ def __len__(self, n):
                             array.array('i', range(10))])
         tm.assert_frame_equal(result, expected, check_dtype=False)
 
+    def test_constructor_iterable(self):
+        class Iter():
+            def __iter__(self):
+                for i in range(10):
+                    yield [1, 2, 3]
+
+        expected = DataFrame([[1, 2, 3]] * 10)
+        result = DataFrame(Iter())
+        tm.assert_frame_equal(result, expected)
+
     def test_constructor_iterator(self):
 
         expected = DataFrame([list(range(10)), list(range(10))])
@@ -1374,10 +1384,6 @@ def test_constructor_miscast_na_int_dtype(self):
         expected = DataFrame([[np.nan, 1], [1, 0]])
         tm.assert_frame_equal(df, expected)
 
-    def test_constructor_iterator_failure(self):
-        with tm.assert_raises_regex(TypeError, 'iterator'):
-            DataFrame(iter([1, 2, 3]))
-
     def test_constructor_column_duplicates(self):
         # it works! #2079
         df = DataFrame([[8, 5]], columns=['a', 'a'])

pandas/tests/series/test_constructors.py

@@ -156,10 +156,14 @@ def test_constructor_series(self):
 
         assert_series_equal(s2, s1.sort_index())
 
-    def test_constructor_iterator(self):
+    def test_constructor_iterable(self):
+        class Iter():
+            def __iter__(self):
+                for i in range(10):
+                    yield i
 
         expected = Series(list(range(10)), dtype='int64')
-        result = Series(range(10), dtype='int64')
+        result = Series(Iter(), dtype='int64')
         assert_series_equal(result, expected)
 
     def test_constructor_list_like(self):