import re


def split(src, join=False):
    """Splits a (possibly multiline) string of Python input into
    a list, adjusting for common indents.

    PARAMETERS:
    src -- str; (possibly) multiline string of Python input
    join -- bool; if True, join output into one string

    DESCRIPTION:
    Indentation adjustment is determined by the first nonempty
    line. The characters of indentation for that line will be
    removed from the front of each subsequent line.

    RETURNS:
    list of strings; lines of Python input
    str; all lines combined into one string if join is True
    """
    src = src.lstrip('\n').rstrip()
    match = re.match('\s+', src)
    length = len(match.group(0)) if match else 0
    result = [line[length:] for line in src.split('\n')]
    if join:
        result = '\n'.join(result)
    return result