how to check input in a loop

C# Corner

Valerie Meunier

3y1kPython

I want to check the input of a variable before going further in the program. I can do it in C# like this:

int= pr=0;
do
Console.Write("Price: ");
while (float.TryParse(Console.ReadLine(), out pr) == false);

As long as the input is not ok, the loop will still run. Never an error is shown.

But how to do that with python? I tried this, but i get always an error when the unput is bad.

while True:
pr=int(input("Price: "))
if type(pr) == int:
break
else:
print("No int")

Thanks.

3 Replies

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Vishal Joshi3y ago

Accepted answer

Hello Valerie,

You can use the code below to get only integer numbers in python.

# input a number
while True:
  try:
    num = int(input("Enter an integer number: "))
    break
  except ValueError:
      print("Please input integer only...")  
      continue

print("num:", num)

Or else you can use isdecimal() to check if the input is decimal. it's similar to TryParse as c#

num = int(num) if num.isdecimal() else None

Thanks

Valerie Meunier3y ago
Thanks
Valerie Meunier3y ago
I tried with try / except and it works, but i wonder whether it exists a specific function like TryParse...