import re


def naturalize(value, max_length=None, integer_places=8):
    """
    Take an alphanumeric string and prepend all integers to `integer_places` places to ensure the strings
    are ordered naturally. For example:

        site9router21
        site10router4
        site10router19

    becomes:

        site00000009router00000021
        site00000010router00000004
        site00000010router00000019

    :param value: The value to be naturalized
    :param max_length: The maximum length of the returned string. Characters beyond this length will be stripped.
    :param integer_places: The number of places to which each integer will be expanded. (Default: 8)
    """
    output = []
    for segment in re.split(r'(\d+)', value):
        if segment.isdigit():
            output.append(segment.rjust(integer_places, '0'))
        elif segment:
            output.append(segment)
    ret = ''.join(output)

    return ret[:max_length] if max_length else ret