Solution Exercise 755: python algorithm to find the list of all prim number contained in given intervall

Exercise 755

Write a Python algorithm in the form of a function which takes as argument an integer n and which returns the list of all the prime integers contained in the interval [n, 2n] Example for n = 9, the function returns the list of the all prim numbers contained in the interval [9, 18] which is L = [11, 13, 17].

Solution

# creating function to test if given number is prim or not
def testPrim(m):
    # Initializing number of divisors
    numberDivisors = 0
    
    # while i is divisor of m we increment numberDivisors
    for i in range(1 , m + 1):
        if(m%i == 0):
            numberDivisors = numberDivisors + 1
            
    # a number is prime if and only if it has two divisors, 1 and itself
    if (numberDivisors == 2):
        return True
    else:
        return False
    
def listPrim(n):
    # initializing the list of prim numbers
    L = []
    for i in range(n , 2*n):
        if testPrim(i):
            L.append(i)
    return L
# Testing algorithm
print("The list of all prim numbers in [9 , 18] is : " , listPrim(9))