ValueError: Invalid Literal for int()

Why This Happens

The int() function can only parse strings representing whole numbers. Strings with letters, spaces, decimals, or special characters cause this error.

The Problem

age = int(input('Enter age: '))  # Fails if user types 'abc'
price = int('19.99')

The Fix

try:
    age = int(input('Enter age: '))
except ValueError:
    print('Please enter a valid number')

price = int(float('19.99'))  # 19

Step-by-Step Fix

1. 1

   Validate input

   Use str.isdigit() or try/except ValueError.

2. 2

   Strip whitespace

   Clean with .strip() before converting.

3. 3

   Use float() for decimals

   Use float() or int(float(s)) for decimal strings.