Question

我只是好奇，如何确保我的input1不等于input2？如果是这种情况，那么提示错误？我已经在我的代码中使用def语句来检查输入的输入是字符串而不是数值，我不认为我实际上可以将它组合起来所以def语句可以做两件事..有什么办法吗？

Answer 1

确保输入有效的功能：

def isvalid(*values):
    for value in values:
        #check a value is invalid 
        if not value in ['pound', 'euro', 'dollar', 'yen']: #etc...
            return False
    return True

主循环：

def get_input():
    a = raw_input("A: ")
    b = raw_input("B: ")
    while (not isvalid(a,b) or a != b):
        print("The inputs were not identical! Please try again.")
        a = raw_input("A: ")
        b = raw_input("B: ") 
    print("{0} = {1}".format(a,b))

get_input()

或者，您可以只有一个功能来实现相同的功能：

def get_input():
    valid_values = ['pound', 'euro', 'dollar', 'yen'] #etc...
    a = raw_input("A: ")
    b = raw_input("B: ")
    while (not (a in valid_values and b in valid_values) or a != b):
        print("The inputs were not valid! Please try again")
        a = raw_input("A: ")
        b = raw_input("B: ") 
    print("{0} = {1}".format(a,b))

注意：not (a in valid_values and b in valid_values)是De Morgan's Law的情况。并且可以重写为not (a in valid_values) or not (b in valid_values)。

制作，以下作为例子：

A: pound
B: orange
The inputs were not valid! Please try again
A: pound
B: euro
The inputs were not valid! Please try again
A: pound
B: pound
pound = pound
>>>

要访问get_input以外输入的值，您可以执行此操作

def get_input():
        valid_values = ['pound', 'euro', 'dollar', 'yen'] #etc...
        a = raw_input("A: ")
        b = raw_input("B: ")
        while (not (a in valid_values and b in valid_values) or a != b):
            print("The inputs were not valid! Please try again")
            a = raw_input("A: ")
            b = raw_input("B: ") 
        print("{0} = {1}".format(a,b))
            return a,b #THIS WAS THE CHANGE

然后调用它：

print("CALLING get_input")
A,B = get_input()
print("CALLED get_input")
#we can now access the result outside of get_input
print(A)
print(B)

将产生：

>>> 
CALLING get_input
A: pound
B: pound
pound = pound
CALLED get_input
pound
pound

在Python 3.x中使用input代替raw_input

确保input1与输入2不同，如果是，则提示错误

1 个答案: