flattening the sequence

flattening.py

from collections.abc import Iterable
def flatten(items, ignore_types = (str,bytes)):
    for x in items:
        if isinstance(x,Iterable) and not isinstance(x,ignore_types):
            yield from flatten(x)
        else:
            yield x

items = [1, 2, [3, 4, [5, 6], 7], 8]
# Produces 1 2 3 4 5 6 7 8
for x in flatten(items):
    print(x)