Python while-loop conditions

Question

I just have a quick question about Python loop conditions in the while loop. I am looking to take input from the user in the form of (score/max score) eg (13/15). I am looking to put this into a while loop that will continuously ask the user to enter the input in this form until they do it right.

So far, I have this

num1 = 0
while num1 !='?/?':
 num1 = raw_input("Please enter your score in the form socre/max(eg. 30/50)")

I know how to check if a condition is true with a single number, such as: while x> 18, or if the condition is a string, such as: while x != 'Start'. I am not sure what to use as the parameters for the condition of 15/20, where these two numbers will be input in this exact form 15/20. Any help would be greatly appreciated.

Thank you

• Ububtunoob: How can I see where this question is located. I have used the search feature and cannot find anything like it?
• timgeb: Click the blue link Asking the user for input until they give a valid response.
• Ububtunoob: I have found other conditions such as single numbers like while x >10 or something. But I cannot find anyway to check if the condition of the input is formatted correctly
• timgeb: Read the blue link Asking the user for input until they give a valid response.
• Ububtunoob: I have read this. In that case, the condition is in an easy form (x > 18). So the user need only enter in a number greater than 18. My question is how can the condition be set to read if the user entered in their response as 15/20? I have used while num1 != '?/?': but this does not work. (I use the ? as a placeholder )

Answer 1

you can use regular expressions for match like

import re
input_str = input("Please enter your score in the form socre/max(eg. 30/50)")
while re.match(r'[0-9]+/[0-9]+',input_str) == None:
 input_str = input("Please enter your score in the form socre/max(eg. 30/50)")
print('matched')

• Ububtunoob: Thank you. I dug around a lot last night and ended up figuring this out myself. I appreciate your constructive input though:)

Answer 2

the code :

import re
score = input("enter score")
while re.match(r'([0-1][0-5])/15',score) == None:
 score = input("enter score")

this will take only score from 0 to 15 out of 15 if u want to change this u can change this condition

[0-1][0-5])/15
[0-1]=stand for first digit
[0-5]=stands for second digit
/15=stands for outof 15

eg if u want out of 30

[0-3][0-9])/30

Answer 3

You can do that the following way:

while True:
 score_input = input("Please enter your score in the form socre/max(eg. 30/50)")
 try:
 score, max_score = score_input.split('/')
 except ValueError:
 continue
 if score > max_score:
 raise ValueError("Score cannot be greater than max. score")
 # Do whatever you wanto to do with score and max_score and remember to break out.

I hope this helps!