grouper and ceiling division (#3)

grouper and ceiling division

setup.cfg

@@ -2,8 +2,15 @@
 universal = 1
 
 [metadata]
-license_file=LICENSE
+license_file = LICENSE
 
 [coverage:run]
 branch = True
 parallel = True
+
+[tool:pytest]
+addopts =
+    --verbose
+    --cov=wimpy
+    --cov-report=html
+    --no-cov-on-fail

setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name='wimpy',
-    version='0.2',
+    version='0.3',
     description='Anti-copy-pasta',
     url='https://github.com/wimglenn/wimpy',
     author='Wim Glenn',

tests/test_util.py

@@ -3,10 +3,12 @@
 
 import pytest
 
-from wimpy.util import cached_property
-from wimpy.util import strip_prefix
-from wimpy.util import strip_suffix
-from wimpy.util import working_directory
+from wimpy import cached_property
+from wimpy import ceiling_division
+from wimpy import grouper
+from wimpy import strip_prefix
+from wimpy import strip_suffix
+from wimpy import working_directory
 
 
 @pytest.mark.parametrize('in_,pre,out', [
@@ -54,3 +56,23 @@ def test_cached_property():
         del a.prop  # .. but you can't delete the descriptor
     assert isinstance(a.prop, float)
     assert isinstance(A.prop, cached_property)
+
+
+@pytest.mark.parametrize('numerator,denominator,result', [
+    (51, 10, 6),
+    (50, 10, 5),
+    (49, 10, 5),
+    (-49, 10, -4),
+])
+def test_ceiling_div(numerator, denominator, result):
+    assert ceiling_division(numerator, denominator) == result
+
+
+
+@pytest.mark.parametrize('iterable,n,fillvalue,result', [
+    (range(6), 2, None, [(0, 1), (2, 3), (4, 5)]),
+    (range(5), 2, None, [(0, 1), (2, 3), (4, None)]),
+    (range(5), 2, 123, [(0, 1), (2, 3), (4, 123)]),
+])
+def test_grouper(iterable, n, fillvalue, result):
+    assert list(grouper(iterable, n, fillvalue)) == result

wimpy/compat.py

@@ -0,0 +1,4 @@
+try:
+    from itertools import zip_longest
+except ImportError:
+    from itertools import izip_longest as zip_longest

wimpy/util.py

@@ -2,8 +2,10 @@
 from contextlib import contextmanager
 from functools import update_wrapper
 
+from wimpy.compat import zip_longest
 
-__all__ = ['cached_property', 'working_directory', 'strip_prefix', 'strip_suffix']
+
+__all__ = ['cached_property', 'working_directory', 'strip_prefix', 'strip_suffix', 'ceiling_division', 'grouper']
 
 
 class cached_property(object):
@@ -45,3 +47,16 @@ def strip_suffix(s, suffix):
     if s.endswith(suffix):
         return s[:len(s) - len(suffix)]
     return s
+
+
+def ceiling_division(numerator, denominator):
+    """Divide and round up"""
+    # Implementation relies on Python's // operator using floor division (round down)
+    # This might surprise C users who expect rounding towards zero
+    return -(-numerator//denominator)
+
+
+def grouper(iterable, n, fillvalue=None):
+    """Yield successive non-overlapping chunks of size n from iterable"""
+    args = [iter(iterable)] * n
+    return zip_longest(*args, fillvalue=fillvalue)