Skip to content

iterators

operationcounter.iterators

operationcounter.iterators module.

Iterators.

exception_generator(ex: type[Exception] = IndexError) -> Generator[Never]

Raise the provided exception on the first yield.

>>> sum(islice(chain([1, 2, 3], exception_generator()), 3))
6
>>> sum(islice(chain([1, 2, 3], exception_generator()), 4))
Traceback (most recent call last):
  ...
IndexError

Used to ensure that iteration doesn't go too far.

Source code in operationcounter\iterators.py 
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
def exception_generator(ex:type[Exception]=IndexError) -> Generator[Never]:
    """Raise the provided exception on the first yield.

    ```python
    >>> sum(islice(chain([1, 2, 3], exception_generator()), 3))
    6
    >>> sum(islice(chain([1, 2, 3], exception_generator()), 4))
    Traceback (most recent call last):
      ...
    IndexError
    ```

    Used to ensure that iteration doesn't go too far.
    """
    def raiser():
        raise ex
    return iter(raiser, object())

group_ordinal(*iterables: Iterable[Any]) -> tuple[Any, ...]

Group elements of iterables by their ordinal.

>>> iterables = (1, 2, 3), [4, 5, 6, 7], {8}
>>> list(group_ordinal(*iterables))
[(1, 4, 8), (2, 5), (3, 6), (7,)]

The elements are grouped in the same order as their iterables (stable).

References
Source code in operationcounter\iterators.py 
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
def group_ordinal(*iterables:Iterable[Any]) -> tuple[Any,...]:
    """Group elements of iterables by their ordinal.

    ```python
    >>> iterables = (1, 2, 3), [4, 5, 6, 7], {8}
    >>> list(group_ordinal(*iterables))
    [(1, 4, 8), (2, 5), (3, 6), (7,)]
    ```

    The elements are grouped in the same order as their iterables (stable).

    References
    ----------
    - [more-itertools PR #1073](https://github.com/more-itertools/more-itertools/pull/1073)
    """
    iterators = list(map(iter, reversed(iterables)))
    result = []
    while iterators:
        result.clear()
        for i in reversed(range(len(iterators))):
            try:
                result.append(next(iterators[i]))
            except StopIteration:
                del iterators[i]
        if result:
            yield tuple(result)