collatz_sequence.py.py

def collatz(number):
  while number != 1:
    if number % 2 == 0:
      number = number // 2
      print(number)
    elif number % 2 == 1:
      number = number * 3 + 1
      print(number)

try:
    num = int(input('Enter a number: '))
    collatz(num)
except ValueError:
    print('Please use whole numbers only.')