即使我输入“ m”或“ f”，性别输入循环也会不断重复

Question

If it's not m or f, repeat prompt until it's either or. I typed m or f, but the loop keeps repeating. Why?

gender = input('m/f? ')

while gender != 'm' or gender != 'f': 
    print("Type 'm' or 'f'") 
    gender = input('m/f? ') 
if gender == 'm': 
    gender = 'him' 
elif gender == 'f': 
    gender = 'her' 

print("It read {}".format(gender))

Answer 1

Just say gender is m . Look at this statement:

while gender != 'm' or gender != 'f':

Is gender!='m' ? No. Or ... Is gender!='f' ? Yes! OK, keep while ing!

You don't want or , you want and

Answer 2

Because of this line : while gender != 'm' or gender != 'f':

Use instead : while gender != 'm' and gender != 'f':

gender cannot simultaneously contain 'm' and 'f'

Answer 3

The basic fundamental

True or True : True

True or False : True

False or True : True

False or False : False

You have to continue asking for input as long as both the conditions are not satisfied.

Or has to be replaced by 'and'.

Answer 4

Try:

gender = raw_input('m/f?')

while True: 
    print("Type 'm' or 'f'") 
    gender = raw_input('m/f? ') 
    if gender=='m' or gender=='f':
        break

if gender == 'm': 
    gender = 'him' 
elif gender == 'f': 
    gender = 'her' 

print("It read {}".format(gender))

Answer 5

There's a number of answers already, but I think the most Pythonic way, which also eliminates the AND/OR confusion is, and is easily extendable if you want to add, say, o for other

while gender not in 'mf':

That is, while gender is not present in the list of genders.

Answer 6

In your while, you are checking to see if either the string gender does not equal 'm' OR 'f', which will always be the case because it cannot be both.

Change or to and to fix this.