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, at which point it will terminate.

Inside the loop, we have a ternary operator (also called a 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.

The first part of the ternary operator divides the number by two if it is even. The else part of the expression (where the number is not even) multiplies the number by three and adds one. Then the counter is incremented by one. When the loop completes, the counter value is returned.

12th Aug 2026 · 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