From 1b8ef510652eec238f835ba8d2b28bfef677833a Mon Sep 17 00:00:00 2001 From: Fabian Neundorf Date: Sat, 20 Jun 2015 00:57:38 +0200 Subject: [PATCH] Add count from 2.7 to 2.6 The future.types.newrange already has a _count method which is now moved to the backports to allow make this public. --- src/future/backports/misc.py | 10 ++++++ src/future/types/newrange.py | 10 ++---- tests/test_future/test_count.py | 57 +++++++++++++++++++++++++++++++++ 3 files changed, 69 insertions(+), 8 deletions(-) create mode 100644 tests/test_future/test_count.py diff --git a/src/future/backports/misc.py b/src/future/backports/misc.py index 03c68c13..71acad27 100644 --- a/src/future/backports/misc.py +++ b/src/future/backports/misc.py @@ -22,6 +22,16 @@ def ceil(x): return int(oldceil(x)) +if PY26: + # itertools.count in Py 2.6 doesn't accept a step parameter + def count(start=0, step=1): + while True: + yield start + start += step +else: + from itertools import count + + # OrderedDict Shim from Raymond Hettinger, python core dev # http://code.activestate.com/recipes/576693-ordered-dictionary-for-py24/ # here to support version 2.6. diff --git a/src/future/types/newrange.py b/src/future/types/newrange.py index 432f11a1..17b6736b 100644 --- a/src/future/types/newrange.py +++ b/src/future/types/newrange.py @@ -21,6 +21,7 @@ from collections import Sequence, Iterator from itertools import islice +from future.backports.misc import count class newrange(Sequence): """ @@ -141,7 +142,7 @@ class range_iterator(Iterator): """An iterator for a :class:`range`. """ def __init__(self, range_): - self._stepper = islice(_count(range_.start, range_.step), len(range_)) + self._stepper = islice(count(range_.start, range_.step), len(range_)) def __iter__(self): return self @@ -150,11 +151,4 @@ def next(self): return next(self._stepper) -# itertools.count in Py 2.6 doesn't accept a step parameter -def _count(start=0, step=1): - while True: - yield start - start += step - - __all__ = ['newrange'] diff --git a/tests/test_future/test_count.py b/tests/test_future/test_count.py new file mode 100644 index 00000000..cc849bd5 --- /dev/null +++ b/tests/test_future/test_count.py @@ -0,0 +1,57 @@ +# -*- coding: utf-8 -*- +""" +Tests for the backported class:`range` class. +""" +from itertools import count as it_count + +from future.backports.misc import count +from future.tests.base import unittest, skip26 + + +class CountTest(unittest.TestCase): + + """Test the count function.""" + + def _test_count_func(self, func): + self.assertEqual(next(func(1)), 1) + self.assertEqual(next(func(start=1)), 1) + + c = func() + self.assertEqual(next(c), 0) + self.assertEqual(next(c), 1) + self.assertEqual(next(c), 2) + c = func(1, 1) + self.assertEqual(next(c), 1) + self.assertEqual(next(c), 2) + c = func(step=1) + self.assertEqual(next(c), 0) + self.assertEqual(next(c), 1) + c = func(start=1, step=1) + self.assertEqual(next(c), 1) + self.assertEqual(next(c), 2) + + c = func(-1) + self.assertEqual(next(c), -1) + self.assertEqual(next(c), 0) + self.assertEqual(next(c), 1) + c = func(1, -1) + self.assertEqual(next(c), 1) + self.assertEqual(next(c), 0) + self.assertEqual(next(c), -1) + c = func(-1, -1) + self.assertEqual(next(c), -1) + self.assertEqual(next(c), -2) + self.assertEqual(next(c), -3) + + def test_count(self): + """Test the count function.""" + self._test_count_func(count) + + @skip26 + def test_own_count(self): + """Test own count implementation.""" + self._test_count_func(it_count) + + +if __name__ == '__main__': + unittest.main()