Develop a Python function to return the prime factorization of a given integer in form of a list.
A **prime number** is a positive integer greater than 1, having only two possible divisors - "1" and the number itself. Examples of prime numbers include `2`, `3`, `5`, etc. A **prime factor** of a number is a prime number that divides the number leaving no remainder. You are required to develop a function that accepts a positive integer `num` as input and returns its prime factors as a list in non-specific order. ### Parameters - `num`: A positive integer to be factorized. ### Return Value - A list consisting of the prime factors of `num`. If the input is "1" or a prime number, return a list with `num` as the only element. ### Examples ```python # Prime factors of 20 are 2, 2, and 5 solution(20) # Should return: [2, 2, 5] # Prime factors of 100 are 2, 2, 5, and 5 solution(100) # Should return: [2, 2, 5, 5] # Prime factors of 8912234 are 2, 47, and 94811 solution(8912234) # Should return: [2, 47, 94811] ```