"""
:func:`include` works like Julia :func:`include` for code splitting.

When a Python code is too large to maintain, it could be split into files,
as well as done in Julia code.

:func:`include` works as Julia built-in :func:`include` to merge code
with given relative path. It is done with Python built-in :func:`exec`
and :mod-attr:`__file__`
"""

def include(path):
    from os.path import normpath, join, dirname

    my_filepath = globals().get('__file__')
    ex_filepath = normpath(join(dirname(globals().get('__file__')), path))
    code = open(ex_filepath).read()

    globals()['__file__'] = ex_filepath
    exec(code, globals())
    if my_filepath is None:
        del globals()['__file__']
    else:
        globals()['__file__'] = my_filepath