functional group iterable

tinylambda · tinylambda · commit b5fc2ef0ca37 · 2020-09-07T19:28:37.000+08:00
diff --git a/functional_program/functional_sequence_operate/functional_organize.py b/functional_program/functional_sequence_operate/functional_organize.py
@@ -0,0 +1,21 @@
+flat = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,]
+flat_iter = iter(flat)
+
+N = 3
+g = (tuple(next(flat_iter) for i in range(N)) for row in range(len(flat) // N))
+print(list(g))
+
+remain_items = []
+for remain_item in flat_iter:
+    remain_items.append(remain_item)
+
+remain_items_len = len(remain_items)
+how_many_to_add = N - remain_items_len
+
+if how_many_to_add < N:
+    for _ in range(how_many_to_add):
+        remain_items.append(None)
+
+    print(tuple(remain_items))
+
+
diff --git a/functional_program/functional_sequence_operate/functional_organize_function.py b/functional_program/functional_sequence_operate/functional_organize_function.py
@@ -0,0 +1,45 @@
+from typing import TypeVar
+from typing import Sequence
+from typing import List
+from typing import Tuple
+from typing import Iterator
+
+
+ItemType = TypeVar('ItemType')
+Flat = Sequence[ItemType]
+Grouped = List[Tuple[ItemType, ...]]
+
+Flat_Iter = Iterator[ItemType]
+Grouped_iter = Iterator[Tuple[ItemType, ...]]
+
+
+def group_by_seq(n: int, sequence: Flat) -> Grouped:
+    flat_iter = iter(sequence)
+    full_sized_items = list(
+        tuple(
+            (next(flat_iter) for i in range(n)))
+        for row in range(len(sequence) // n)
+    )
+
+    trailer = tuple(flat_iter)
+    if trailer:
+        return full_sized_items + [trailer]
+    else:
+        return full_sized_items
+
+
+def group_by_iter(n: int, iterable: Flat_Iter) -> Grouped_iter:
+    row = tuple(next(iterable) for i in range(n))
+    while row:
+        yield row
+        row = tuple(next(iterable) for i in range(n))
+
+
+if __name__ == '__main__':
+    flat = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, ]
+    g = group_by_seq(3, flat)
+    print(g)
+
+    flat2 = [1]
+    print(list(group_by_iter(3, iter(flat))))
+
