在 if 语句中调用函数 - Python3

Question

因此，我尝试使用 Python3 在终端中编写登录对话，但由于某种原因，此代码：def start():    login_signin_Confirmation = input("Welcome! Do you wish to log-in to your account or sign up to this platform? \n")    if login_signin_Confirmation == "login":                login()    else:        signup()       start()def login():    login_username = input("Great! start by typing in your username.")    if login_username in users:        print("Welcome Back, {login_username}")login()提示我此错误消息：Welcome! Do you wish to log-in to your account or sign up to this platform? loginTraceback (most recent call last):  File "login.py", line 22, in <module>    start()  File "login.py", line 19, in start    login()NameError: name 'login' is not defined刚开始一些我不太确定我做错了什么，而且我找不到有同样问题的人......

Answer 1

正如其他人指出的，您需要首先定义，然后调用函数：

# imports first

# now definitions of functions

def start():

    login_signin_Confirmation = input("Welcome! Do you wish to log-in to your account or sign up to this platform? \n")

    if login_signin_Confirmation == "login":

        login()

    else:

        signup()       

def signup():

    pass

def login():

    login_username = input("Great! start by typing in your username.")

    if login_username in users:

        print("Welcome Back, {login_username}")

# main 

def main():

    start()

# guard multiprocess context

if __name__ == '__main__':

    main()