Question

如果错误，我希望其他语句显示一次。请查看我尝试过的代码。

lists = ['apple','grape','pineapple','orange']

password = "xyz"
def pass1():
    for i in lists:
        if i == password:
            print("Accepted!", "Password : " + i)
            break
        else:
            print("Password not found! Try again")
pass1()

输出：

Password not found! Try again
Password not found! Try again
Password not found! Try again
Password not found! Try again

Process finished with exit code 0

Answer 1

如果我正确理解了您的问题，则可以通过删除else来完成此操作，如果循环结束并且您在列表中找不到密码，则该密码不存在。

lists = ['apple','grape','pineapple','orange']

password = "xyz"
def pass1():
    for i in lists:
        if i == password:
            print("Accepted!", "Password : " + i)
            return
    print("Password not found! Try again")
pass1()

另一种更Python化的方式

def pass2():
    if password in lists:
        print(print("Accepted!", "Password : " + lists.index(password)))
    else:
        print("Password not found! Try again")
pass2()

我不明白您为什么不将密码作为参数传递？

也许考虑按照以下步骤进行操作

def pass3(password, lists):
    if password in lists:
        print(print("Accepted!", "Password : " + lists.index(password)))
    else:
        print("Password not found! Try again")

lists = ['apple','grape','pineapple','orange']
password = "xyz"
pass3(password, lists)

Answer 2

实际上，如果您只想检查列表中的值，则不需要循环，只需尝试以下操作：

def pass1():
    if password in lists:
        print("Accepted!", "Password : " + password)
    else:    
        print("Password not found! Try again")

但是如果您仍然想遍历列表，则可以使用return这样：

def pass1():
    for i in lists:
        if i == password:
            return print("Accepted!", "Password : " + i)
    return print("Password not found! Try again")

因为如果不使用return，即使密码为true，仍然会打印最后一个代码。

Answer 3

在else上使用for loop的另一种方法
else block仅在每个项目都用尽时执行：

lists = ['apple','grape','pineapple','orange']

password = "xyz"
def pass1():
    for i in lists:
        if i == password:
            print("Accepted!", "Password : " + i)
            break
    else:
        print("Password not found! Try again")
pass1()

我希望输出在for循环中显示一次

3 个答案: