add one_tuple

CHANGELOG.md

@@ -2,3 +2,4 @@
 
 * more pydoc for `satella.files`
 * add `try_unlink`
+* add `one_tuple`

docs/coding/transforms.rst

@@ -7,6 +7,11 @@ split_shuffle_and_join
 .. autofunction:: satella.coding.transforms.split_shuffle_and_join
 
 
+one_tuple
+---------
+
+.. autofunction:: satella.coding.transforms.one_tuple
+
 stringify
 ---------
 

satella/__init__.py

-__version__ = '2.9.5_a2'
+__version__ = '2.9.5'

satella/coding/transforms/__init__.py

@@ -2,7 +2,8 @@ import collections
 import random
 import typing as tp
 
-__all__ = ['stringify', 'split_shuffle_and_join']
+__all__ = ['stringify', 'split_shuffle_and_join', 'one_tuple']
+
 
 
 def _stringify_none(str_none, stringifier):
@@ -14,6 +15,21 @@ def _stringify_none(str_none, stringifier):
 T = tp.TypeVar('T')
 
 
+def one_tuple(x: tp.Iterable[T]) -> tp.Iterator[tp.Tuple[T]]:
+    """
+    Change a sequence of iterables into a sequence that displays each element as
+    a part of one-element tuple. Essentially syntactic sugar for:
+
+    >>> for y in x:
+    >>>     yield y,
+
+    :param x: sequence to tupleify
+    :return: a iterator of one-element tuples
+    """
+    for y in x:
+        yield y,
+
+
 def split_shuffle_and_join(entries: tp.List[T],
                            whether_to_shuffle: tp.Callable[[T], bool] = lambda x: True,
                            not_shuffled_to_front: bool = True) -> tp.List[T]:

tests/test_coding/test_transforms.py

 import unittest
 
-from satella.coding.transforms import stringify, split_shuffle_and_join
+from satella.coding.transforms import stringify, split_shuffle_and_join, one_tuple
 
 
 class MyTestCase(unittest.TestCase):
+    def test_one_tuple(self):
+        self.assertEqual(list(one_tuple([1, 2, 3])), [(1, ), (2, ), (3, )])
+
     def test_split_shuffle_and_join(self):
         x = [1, 2, 3, 4]
         x = split_shuffle_and_join(x, lambda y: y % 2 == 0)