Ternary operator

Collatz Conjecture
Collatz Conjecture in Python 
def steps(number):
    if number <= 0:
        raise ValueError("Only positive integers are allowed")
    counter = 0
    while number != 1:
        number = number / 2 if number % 2 == 0 else number * 3 + 1
        counter += 1
    return counter

This approach starts with checking if the number is less than or equal to zero. If it is, then a ValueError is raised.

After that, a counter variable is assigned to zero. Then we start a while loop that will run until the number is equal to one. Meaning the loop won't run if the number is already one.

Inside the loop we have a ternary operator or [conditional expression][conditional-expression]. A ternary operator/conditional expression can be viewed as a one-line if/else statement. Using a one-line construct can make the code more concise.

We assign the number value to the result of the ternary operator. The ternary operator/conditional expression checks if the number is even. If it is, then we divide it by two. If the number is not even, we multiply by three and add one. Then the counter is incremented by one. When the loop completes, we return the counter value.

4th Dec 2024 · Found it useful?

Other Approaches to Collatz Conjecture in Python

Other ways our community solved this exercise
counter = 0
while number != 1:
    if number % 2 == 0:
        number /= 2
    else:
        number = number * 3 + 1
    counter += 1
return counter
If/Else

Use if and else 

def steps(number):
    if number < 1:
        raise ValueError("Only positive integers are allowed")
    if number == 1:
        return 0
    number = number / 2 if number % 2 == 0 else number * 3 + 1
    return 1 + steps(number)
Recursion

Use recursion