Multiple while/try to check if value is an array between 0 and 1

Question

I want to do a while loop which ask user to enter value until the value is a float value between 0 and 1

Current code is

while True:
   seuil =input("Please enter a threshold between 0 and 1 (e.g 0.7):")
   try:
       seuil = float(seuil)
   except ValueError as e:
       print("Enter  numeric value")
   if (seuil <0 or seuil >1):
      raise ValueError('Please enter value between 0 and 1') 
   else:
       break

Problems:

if value is not between 0 and 1 I have an error message but the code doesnt ask again to user to enter a value

if value is a string then got following error message

TypeError: '<' not supported between instances of 'str' and 'int'

any help appreciated

if the conversion to `float` fails the code still continues to the line `if (seuil <0 or seuil >1):` and you will get your error. — hiro protagonist, Sep 04 '19 at 07:41

ababak · Accepted Answer · 2019-09-04T07:47:56.607

2

When you catch an exception you should not continue treating the variable as int. Here's the corrected code:

while True:
   seuil = input("Please enter a threshold between 0 and 1 (e.g 0.7):")
   try:
       seuil = float(seuil)
   except ValueError as e:
       print("Enter numeric value")
       continue
   if (seuil < 0 or seuil > 1):
      print('Please enter value between 0 and 1')
   else:
       break

edited Sep 04 '19 at 07:47

answered Sep 04 '19 at 07:41

ababak

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That code will also break when the `ValueError` is raised – Adirio Sep 04 '19 at 07:44
Yes, sure. Updated the code to fix this. – ababak Sep 04 '19 at 07:48

Multiple while/try to check if value is an array between 0 and 1

1 Answers1