python - Loop until an input is of a specific type

Question

I'm trying to make a program that repeatedly asks an user for an input until the input is of a specific type. My code:

value = input("Please enter the value")

while isinstance(value, int) == False:
     print ("Invalid value.")
     value = input("Please enter the value")
     if isinstance(value, int) == True:
         break

Based on my understanding of python, the line

if isintance(value, int) == True
    break

should end the while loop if value is an integer, but it doesn't.

My question is:
a) How would I make a code that would ask the user for an input, until the input is an integer?
b) Why doesn't my code work?

Answer 1

The reason your code doesn't work is because input() will always return a string. Which will always cause isinstance(value, int) to always evaluate to False.

You probably want:

value = ''
while not value.strip().isdigit():
     value = input("Please enter the value")