Source code for faust.utils.functional
"""Functional utilities."""
from itertools import groupby
from typing import Iterable, Iterator, Optional, Sequence, TypeVar
from mode.utils.typing import Deque
__all__ = ['consecutive_numbers', 'deque_prune', 'deque_pushpopmax']
T = TypeVar('T')
[docs]def consecutive_numbers(it: Iterable[int]) -> Iterator[Sequence[int]]:
"""Find runs of consecutive numbers.
Notes:
See https://docs.python.org/2.6/library/itertools.html#examples
"""
for _, g in groupby(enumerate(it), lambda a: a[0] - a[1]):
yield [a[1] for a in g]
[docs]def deque_prune(l: Deque[T], max: int = None) -> Optional[T]:
"""Prune oldest element in deque if size exceeds ``max``."""
if max is not None:
size = len(l)
if size > max:
return l.popleft()
return None
[docs]def deque_pushpopmax(l: Deque[T], item: T, max: int = None) -> Optional[T]:
"""Append to deque and remove oldest element if size exceeds ``max``."""
l.append(item)
return deque_prune(l, max)