"or" in a while loop confusion

Question

So I am going back to basics with Python, after a long stint in JS. And I just something out which goes against what I thought it would do.

I have the following code:

name = ''
while name != 'your name' or 'your name.':
    print('Please type your name.')
    name = input()
print('Thank you!')

However, when I run the script, and input either 'your name' or 'your name' the script just keeps looping and doesn't come out of the loop.

I am confused.

score 2 · Accepted Answer · answered Jul 14 '18 at 22:29

2

That's because your second condition is just a string 'your name.', which is always true. You need to add name != 'your name.' to the second condition:

while name != 'your name' or name != 'your name.':

answered Jul 14 '18 at 22:29

Spencer Wieczorek

21,229
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Ah yes! Thanks, silly me! – Baba.S Jul 14 '18 at 22:31
2

You could also create a set of valid strings and test for containment: `while name not in {'your name', 'your name.'}:` – Peter Wood Jul 14 '18 at 22:31
Or you could use `while not name.startswith('your name')` – Anton vBR Jul 14 '18 at 22:33

score 0 · Answer 2 · answered Jul 14 '18 at 22:36

0

Here is another way:

while True:
    print('Please type your name.')
    name = input()
    if name.startswith('your name'):
        print('invalid')
    else:
        break

print('Thank you!')

answered Jul 14 '18 at 22:36

Anton vBR

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"or" in a while loop confusion

2 Answers2

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