bites 222 - itertools islice

Author: naipawat.poo@student.mahidol.ac.th

.gitignore

@@ -70,3 +70,4 @@
 /187/README.md
 /148/README.md
 /197/README.md
+/222/README.md

222/grouping.py

@@ -0,0 +1,27 @@
+import types
+from itertools import islice
+
+
+def group(iterable, n):
+    """Splits an iterable set into groups of size n and a group
+       of the remaining elements if needed.
+
+       Args:
+         iterable (list): The list whose elements are to be split into
+                          groups of size n.
+         n (int): The number of elements per group.
+
+       Returns:
+         list: The list of groups of size n,
+               where each group is a list of n elements.
+    """
+    iterable_list = list(iterable)
+    return [list(islice(iterable_list, x, x+n)) for x in range(0, len(iterable_list), n)]
+
+
+if __name__ == '__main__':
+    iterable = [1, 2, 3, 4, 5, 6, 7, 8, 9]
+    gen = (i for i in iterable)
+    n = 3
+    ret = group(gen, n)
+    print(ret)

222/test_grouping.py

@@ -0,0 +1,47 @@
+import types
+
+from grouping import group
+
+
+def test_split_10_ints_by_3():
+    iterable = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
+    n = 3
+    actual = group(iterable, n)
+    expected = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]
+    assert actual == expected
+
+
+def test_passing_in_tuple():
+    iterable = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
+    n = 3
+    actual = group(iterable, n)
+    expected = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]
+    assert actual == expected
+
+
+def test_passing_in_generator():
+    iterable = [1, 2, 3, 4, 5, 6, 7, 8, 9]
+    gen = (i for i in iterable)
+    assert isinstance(gen, types.GeneratorType)
+    n = 3
+    actual = group(gen, n)
+    expected = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
+    assert actual == expected
+
+
+def test_different_iterable_size():
+    iterable = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] * 2
+    n = 3
+    actual = group(iterable, n)
+    expected = [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 1, 2],
+                [3, 4, 5], [6, 7, 8], [9, 10]]
+    assert actual == expected
+
+
+def test_different_n():
+    iterable = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] * 2
+    n = 5
+    actual = group(iterable, n)
+    expected = [[1, 2, 3, 4, 5], [6, 7, 8, 9, 10],
+                [1, 2, 3, 4, 5], [6, 7, 8, 9, 10]]
+    assert actual == expected