collatz.py

def get_number()
  while True:    #(!num) through a big error
      try:
        print('Please enter a number for the Collatz sequence:')
        num = int(input()) # Prompt for a number
        return num
        break
    except ValueError: # If we couldn't make it an int...
        print("enter an integer") # ... complain


def collatz(n):
  # return next number after n in the collatz sequence
  if n % 2 == 0:
			n = n // 2
			print(n)
			return n

		else:
			n = n * 3 + 1
			print(n)
			return n


def main():
  number = get_number()
  while number != 1:
    number = collatz(number)
    
main()