continuous loop until the user has entered a valid input in python

Question

Somebody please help me with the following code. The purpose of the code is to continue the loop unless the user has entered a valid input.

marks1 = int(input("Enter Marks1: "));
while(marks<0 or marks>100):
       print("Please enter a valid input");
       continue
marks2 = int(input("Enter marks2: "));
while(marks2<0 or marks2>100):
       print("Please enter a valid input");
       continue
marks3 = int(input("Enter marks3: "));
while(marks3<0 or marks3>100):
      print("Please enter a valid input");
      continue

But when I run program. It gives the continuous output of:

"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"
"Please enter a valid number"

Can I know what is the problem in my code?

score 0 · Answer 1 · answered Nov 29 '15 at 02:29

The fixes I made:

The while loop doesn't need parentheses.
The first while loop was using marks and not marks1.
Took out the semi-colons on the first and third lines. They're unnecessary here.
Added another input line. You need to give the user a way to re-enter a valid input.
Took out the continue. It's unnecessary here.

The fixed code (for one section):

marks1 = int(input("Enter Marks1: "))
while marks1<0 or marks1>100:
       print("Please enter a valid input")
       marks1 = int(input("Enter Marks1: "))

continuous loop until the user has entered a valid input in python

1 Answers1