Function primeFactorization

other/primelib.py:140–182

input: positive integer 'number' returns a list of the prime number factors of 'number'

(number)

# -----------------------------------------
    
def primeFactorization(number):
    """
        input: positive integer 'number' 
        returns a list of the prime number factors of 'number'
    """

    import math    # for function sqrt
    
    # precondition
    assert isinstance(number,int) and number >= 0, \
    "'number' must been an int and >= 0"
    
    ans = [] # this list will be returns of the function.

    # potential prime number factors.

    factor = 2    

    quotient = number
    
    
    if number == 0 or number == 1:
        
        ans.append(number)
        
    # if 'number' not prime then builds the prime factorization of 'number'    
    elif not isPrime(number):
    
        while (quotient != 1):
            
            if isPrime(factor) and (quotient % factor == 0):
                    ans.append(factor)
                    quotient /= factor
            else:
                    factor += 1
    
    else:
        ans.append(number)
    
    # precondition
    assert isinstance(ans,list), "'ans' must been from type list"    
    
    return ans
    

# -----------------------------------------