Trying to end while loop Python

Question

I have the following code that should end when my number is no longer a certain tuple, such as (1,0) or (2,0). But when I run my code it runs infinitely or not at all cant figure out the problem.

import random

START = (random.randrange(0, 4), random.randrange(0, 4))

print(START)

while START==(1, 0) or (2, 0) or (1, 1) or (3, 2):

    START = (random.randrange(0, 4), random.randrange(0, 4))

else:

    print(START)

Celius Stingher · Accepted Answer · 2021-11-15T00:18:41.637

2

This is a common error, evaluating an argument followed by OR and different values will always evaluate to true. You can read a more in-depth answer here.

A good solution to avoid having to write multiple comparisons is to use the operator in. Replace:

while START==(1, 0) or (2, 0) or (1, 1) or (3, 2):

With

while START in [(1,0),(2,0),(1,1),(3,2)]:

edited Nov 15 '21 at 00:18

answered Nov 15 '21 at 00:15

Celius Stingher

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Thanks for the comment! I have edited the answer to fix the typo. – Celius Stingher Nov 15 '21 at 00:16
1

Missed that, in fact I meant to say always instead of almost, because it's the title of the question asked in 2013 :P – Celius Stingher Nov 15 '21 at 00:18

score 1 · Answer 2 · answered Nov 15 '21 at 00:14

1

try

while START==(1, 0) or START==(2, 0) or START==(1, 1) or START==(3, 2):

or

while START in [(1, 0), (2, 0), (1, 1), (3,2)]:

the else shouldn't be needed.

answered Nov 15 '21 at 00:14

njp

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score 0 · Answer 3 · answered Nov 15 '21 at 00:17

0

Your while condition is incorrect causing it to be in a infinite loop. Either try doing while START==(1, 0) or START==(2, 0) or START==(1, 1) or START==(3, 2): or put the tuples into a list and just do START in list.

answered Nov 15 '21 at 00:17

Stoobish

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Trying to end while loop Python

3 Answers3