Made it so that named tuples are not wrapped by things like get item

CHANGELOG.md

@@ -3,6 +3,9 @@
 ### Internal Changes
 * Changed all relative imports to absolute imports with `__future__.absolute_import`
 
+### Bug Fixes
+* Fixed case where `_wrap` is changing named tuples to arrays when it should preserve them
+
 ## Release 0.4.1
 Fix python 3 build error due to wheel installation of enum34. Package no longer depends on enum34
 

functional/pipeline.py

@@ -14,7 +14,7 @@
 import future.builtins as builtins
 
 from functional.lineage import Lineage
-from functional.util import is_iterable, is_primitive, identity, CSV_WRITE_MODE
+from functional.util import is_iterable, is_primitive, is_namedtuple, identity, CSV_WRITE_MODE
 from functional import transformations
 
 
@@ -1436,7 +1436,7 @@ def _wrap(value):
     """
     if is_primitive(value):
         return value
-    if isinstance(value, dict) or isinstance(value, set):
+    if isinstance(value, dict) or isinstance(value, set) or is_namedtuple(value):
         return value
     elif isinstance(value, collections.Iterable):
         return Sequence(value)

functional/test/test_functional.py

@@ -710,8 +710,9 @@ def test_wrap(self):
         self.assert_type(_wrap((1, 2)))
         self.assert_not_type(_wrap(1))
         self.assert_not_type(_wrap(1.0))
-        self.assert_not_type("test")
-        self.assert_not_type(True)
+        self.assert_not_type(_wrap("test"))
+        self.assert_not_type(_wrap(True))
+        self.assert_not_type(_wrap(Data(1, 2)))
 
     def test_wrap_objects(self):
         class A(object):

functional/test/test_util.py

@@ -1,7 +1,11 @@
 from __future__ import absolute_import
 
 import unittest
-from functional.util import ReusableFile
+from collections import namedtuple
+
+from functional.util import ReusableFile, is_namedtuple
+
+Data = namedtuple('Tuple', 'x y')
 
 
 class TestUtil(unittest.TestCase):
@@ -12,3 +16,9 @@ def test_reusable_file(self):
         iter_1 = iter(license_file_lf)
         iter_2 = iter(license_file_lf)
         self.assertEqual(list(iter_1), list(iter_2))
+
+    def test_is_namedtuple(self):
+        self.assertTrue(is_namedtuple(Data(1, 2)))
+        self.assertFalse(is_namedtuple((1, 2, 3)))
+        self.assertFalse(is_namedtuple([1, 2, 3]))
+        self.assertFalse(is_namedtuple(1))

functional/util.py

@@ -47,6 +47,23 @@ def is_primitive(val):
         or isinstance(val, bytes)
 
 
+def is_namedtuple(val):
+    """
+    Use Duck Typing to check if val is a named tuple. Checks that val is of type tuple and contains
+    the attribute _fields which is defined for named tuples.
+    :param val: value to check type of
+    :return: True if val is a namedtuple
+    """
+    val_type = type(val)
+    bases = val_type.__bases__
+    if len(bases) != 1 or bases[0] != tuple:
+        return False
+    fields = getattr(val_type, '_fields', None)
+    if not isinstance(fields, tuple):
+        return False
+    return all(isinstance(n, str) for n in fields)
+
+
 def identity(arg):
     """
     Function which returns the argument. Used as a default lambda function.