Creating Collatz sequences/orbits from an integer.

collatz.py

def collatz(n):
    """The Collatz operator: If n is even return n/2 else return 3n+1."""
    
    # If n is even then divide by 2.
    if n%2==0:
        return int(n/2)
    
    # Otherwise return 3n+1
    else:
        return (3*n)+1
      

def collatz_orbit(n):
    """Calculate the sequence of integers by repeatedly applying the Collatz
    operator until the result is 1. Return the resulting sequence."""
    
    # Initialise the orbit (sequence of numbers).
    orbit = []
    
    # Loop until n=1.
    while n>1:
        
        # Add n to the orbit.
        orbit.append(n)
        
        # Apply the collatz rule to get a new n
        n = collatz(n)
        
    # Return the orbit with the root (1).
    return orbit+[1]