from typing import Iterable
from typing import Any
from typing import List
import itertools


def flatten(val: Iterable[Iterable[Any]]) -> List[Any]:
    """
    Flatens a list of list into a list

    >>> flatten( [['abc','def'],[12,34,46],[3.14, 2.22]])
    ['abc', 'def', 12, 34, 46, 3.14, 2.22]
    """
    return list(itertools.chain(*val))