gistfile1.py

# -*- coding: utf-8 -*-


def parse_input_string(strs):
    import shlex
    parsed = shlex.split(cmd)
    print(parsed)
    return parsed
cmd = 'hoge | moge 1 | insert_delimiter ! | whitespace'
parsed = parse_input_string(cmd)

def parse_command(parsed):
    ret = []
    current = []
    while parsed:
        c = parsed.pop(0)
        if c == "|":
            ret.append(current)
            current = []
        else:
            current.append(c)
    ret.append(current)
    return ret
cmds = parse_command(parsed)
print(cmds)

def register_functions():
    def echo(barg, arg=''):
        if arg:
            ret = arg
        elif barg:
            ret = barg
        else:
            ret = ''

        return ret

    def moge(barg, arg='?'):
        return '!moge' + barg + arg + 'moge!'

    def whitespace(barg):
        return ' '.join([c for c in barg])

    def insert_delimiter(barg, delimiter=','):
        return '{}'.format(delimiter).join([c for c in barg])

    fns = [echo, moge, whitespace, insert_delimiter]
    return fns


def get_fn(fn_str):
    for fn in register_functions():
        if fn.__name__ == fn_str:
            return fn

    return None

def emit(cmds):
    default_func = get_fn('echo')
    ret =''

    while len(cmds) > 0:
        _c = cmds.pop(0)
        fn_str = _c[0]
        args = _c[1:]

        if callable(get_fn(fn_str)):
            ret = get_fn(fn_str)(ret, *args)
        else:
            ret = default_func(''.join(_c))

    print('no commands')
    print(ret)
emit(cmds)

['hoge', '|', 'moge', '1', '|', 'insert_delimiter', '!', '|', 'whitespace']
[['hoge'], ['moge', '1'], ['insert_delimiter', '!'], ['whitespace']]
no commands
! ! m ! o ! g ! e ! 1 ! m ! o ! g ! e ! !