Question

Using Python:

A Prime number is an integer greater than 1 that cannot be formed by multiplying two smaller integer other than 1 and itself. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1. In this question you will write a program that takes a sequence of integers from the user and display all the prime numbers contained in that sequence.

We will separate this question in 2 steps Step 1 (5 pts)

Write a script that accepts a sequence of positive integer from the user and display all the prime numbers from that sequence. Your program should accept and save in a list the input from the user until the value -1 is entered. Your program should also make sure that only positive values are entered. You can assume the users only enter integers.

Step 2 (5 pts) We can improve the program usability by adding the following functions: - A function is_prime that receives an integer as parameter, check if this integer is a prime number and returns a boolean value depending on the result. - A function find_primes that receives the user sequence as parameter and use the function is_prime to figure out which are the prime values. The function then returns a list containing all the prime values contained in the user sequence.

Your user input script should be similar as in part 1 and use the result of the find_primes function to display the list of prime numbers.

The following is a sample output. User inputs is displayed in bold

Enter a value: 5 Enter the next value: 8 Enter the next value: -6 Incorrect Value Enter another value: 6 Enter the next value: 3 Enter the next value: 5 Enter the next value: 12 Enter the next value: 45 Enter the next value: 21 Enter the next value: 8 Enter the next value: -1 You entered the following values : [5, 8, 6, 3, 5, 12, 45, 21, 8] From you list, the prime numbers are : {3, 5}

Answer 1

Thanks for the question.

Below is the code you will be needing  Let me know if you have any doubts or if you need anything to change.

Thank You !!

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# step 2
def is_prime(num):
    for i in range(2, num):
        if (num % i) == 0:return False
    else:
        return True


#A function find_primes that receives the user sequence as parameter
def find_primes(user_numbers):
    primes=[]
    for n in user_numbers:
        if is_prime(n) and n not in primes:primes.append(n)
    primes.sort()
    return primes

    # step 1
user_numbers=[]
while True:
    num = int(input('Enter a value: '))
    if num==-1:break
    elif num<0:print('Incorrect Value')
    else:user_numbers.append(num)

print('You entered the following values:',user_numbers)

prime_numbers=[]
for n in user_numbers:
    if is_prime(n):prime_numbers.append(n)

primes=find_primes(user_numbers)
print('From you list, the prime numbers are:',primes)