python can user enter value None code example
Example: python default input
# Python 3:
age = input('Enter your age: ') or 18
# Older versions:
age = int(raw_input('Enter your age: ') or 18)
# Python 3:
age = input('Enter your age: ') or 18
# Older versions:
age = int(raw_input('Enter your age: ') or 18)