Question

我是python的新手，在我的预科课程中，我学习了BBC BASIC，这非常基础，我在那里学到了许多坏习惯。我在codecademy的帮助下学习了python，但是，如何在if语句中调用函数？在我的第一个if语句中，我调用了函数mainMenu(menu)，但它没有显示函数内容。为什么？

（顺便说一句，我只是想做一台ATM机只是为了练习我学到的东西并巩固它

print "Hello ! Welcome to JD's bank"
print
print "Insert bank card and press any key to procede"
print
raw_input()

passcode = 1111

attempts = 0

while passcode == 1111:

    passcodeInsertion= raw_input("Please insert your 4-digit code: ")
    print""


    if passcodeInsertion == str(passcode):
        print "This is working" #testing-----
        print ""
        mainMenu(menu)


    elif attempts < 2:

        print "Sorry ! Wrong passcode"
        attempts += 1

        print "------------------------------------------------"
        print ""
        print"Try again !! This is your " + str(attempts) + " attempt"
        print
        print "------------------------------------------------"
        print   

    else:
        print""
        print "Your card is unfortunately now blocked" 
        exit()

def mainMenu(menu):

    print "------------------------------------------------"
    print "Select one of this options"
    print "1. Check Balance"
    print "2. Withdraw Money"
    print "3. Deposit Money "
    print "0. Exit "
    print "------------------------------------------------"

Answer 1

print "Hello ! Welcome to JD's bank"
print
print "Insert bank card and press any key to procede"
print
raw_input()

def mainMenu():

    print "------------------------------------------------"
    print "Select one of this options"
    print "1. Check Balance"
    print "2. Withdraw Money"
    print "3. Deposit Money "
    print "0. Exit "
    print "------------------------------------------------"

passcode = 1111

attempts = 0

while passcode == 1111:

    passcodeInsertion= raw_input("Please insert your 4-digit code: ")
    print""


    if passcodeInsertion == str(passcode):
        print "This is working" #testing-----
        print ""
        mainMenu()


    elif attempts < 2:

        print "Sorry ! Wrong passcode"
        attempts += 1

        print "------------------------------------------------"
        print ""
        print"Try again !! This is your " + str(attempts) + " attempt"
        print
        print "------------------------------------------------"
        print   

    else:
        print""
        print "Your card is unfortunately now blocked" 
        exit()

尝试以上方法。将mainMenu移到顶部，您不需要任何参数。

Answer 2

尝试将MainMenu功能置于顶部。这是因为在Python中，函数定义必须在它们使用之前。此外，您从未定义menu，因此我们可以摆脱它。

def mainMenu():
    print "------------------------------------------------"
    print "Select one of this options"
    print "1. Check Balance"
    print "2. Withdraw Money"
    print "3. Deposit Money "
    print "0. Exit "
    print "------------------------------------------------"

print "Hello ! Welcome to JD's bank"
print
print "Insert bank card and press any key to procede"
print
raw_input()

passcode = 1111

attempts = 0

while passcode == 1111:

    passcodeInsertion= raw_input("Please insert your 4-digit code: ")
    print""


    if passcodeInsertion == str(passcode):
        print "This is working" #testing-----
        print ""
        mainMenu()


    elif attempts < 2:

        print "Sorry ! Wrong passcode"
        attempts += 1

        print "------------------------------------------------"
        print ""
        print"Try again !! This is your " + str(attempts) + " attempt"
        print
        print "------------------------------------------------"
        print   

    else:
        print""
        print "Your card is unfortunately now blocked" 
        exit()

Answer 3

与在C ++中一样，必须在使用它的代码区域之前定义该函数。因此，您的代码应为：

def mainMenu():

    print "------------------------------------------------"
    print "Select one of this options"
    print "1. Check Balance"
    print "2. Withdraw Money"
    print "3. Deposit Money "
    print "0. Exit "
    print "------------------------------------------------"

print "Hello ! Welcome to JD's bank"
print
print "Insert bank card and press ENTER to proceed"
print
raw_input()

passcode = 1111
attempts = 0

while passcode == 1111:
        passcodeInsertion= raw_input("Please insert your 4-digit code: ")
    print
    if passcodeInsertion == str(passcode):
        print "This is working" #testing-----
        print ""
        mainMenu()  #removed menu as you have not defined it above
    elif attempts < 2:
        print "Sorry ! Wrong passcode"
        attempts += 1

        print "------------------------------------------------"
        print ""
        print"Try again !! This is your " + str(attempts) + " attempt"
        print
        print "------------------------------------------------"
        print   
    else:
        print""
        print "Your card is unfortunately now blocked" 
        exit()

在其他地方，您可以将功能放置在while循环的正上方，但要确保您的功能位于调用它的区域之上。

如何在python中调用if语句中的某个函数？

3 个答案: