需求是检测男女双方是否互相选择，输出互相选择的人，这是我写的源码：
import os import sys all = [] global c,i input("欢迎使用程序，输入quit以退出，录入数据格式：如：男\n1心仪女1，则输入：男1 = 女1，按下回车继续...") while True: a = [] expression = input("请录入数据：") if expression == "quit": for i in all: a = i b = a c = exec(f"{b} = None") d = all[c] o = b exec(f"v = \"{b}\"") if v == o: print(f"{o}和{v}配对成功") else: expression = expression.strip() expression.replace('=','=') a = expression.split('=') b = a[0] c = a[1] z = str(c) all.append(exec(f"{b} = \"{z}\"")) `` python报错：`SyntaxError: can't assign to keyword`