iterfunction.py 文件源码

def flatmap(func, iterable):
    """
    Map function to iterable and flatten.

    >>> f = lambda n: str(n) * n
    >>> list( flatmap(f, [1, 2, 3]) )
    ['1', '2', '2', '3', '3', '3']

    >>> list( map(f, [1, 2, 3]) )  # map instead of flatmap
    ['1', '22', '333']

    :param function func: Function to map on iterable.
    :param iterable iterable: Any iterable, e.g. list, range, ...
    :return: Iterator of iterable elements transformed via func and flattened.
    :rtype: Iterator
    """
    return itt.chain.from_iterable(map(func, iterable))