def foo(s): def foo_helper(level=0): try: token = next(tokens) except StopIteration: if level != 0: raise Exception('missing closing paren') else: return [] if token == ')': if level == 0: raise Exception('missing opening paren') else: return [] elif token == '(': return [foo_helper(level+1)] + foo_helper(level) else: return [token] + foo_helper(level) tokens = iter(s) return foo_helper()和，
>>> foo('a((b(c))d)(e)')['a', [['b', ['c']], 'd'], ['e']]
