Assignment 3

  • Modify the code that prints every prime number between 1 and 100 to only print every other prime number.
  • Extra credit if you can modify the code to speed it up.

In [ ]:
for num in range(1,101): # for-loop through the numbers
    prime = True # boolean flag to check the number for being prime
    for i in range(2,num): # for-loop to check for "primeness" by checking for divisors other than 1
        if (num%i==0): # logical test for the number having a divisor other than 1 and itself
            prime = False # if there's a divisor, the boolean value gets flipped to False
    if prime: # if prime is still True after going through all numbers from 1 - 100, then it gets printed
        print(num)

In [15]:
prime_list=[]
for num in range(1,101):
    prime = True
    for i in range(2,num):
        if (num%i==0):
            prime = False
    if prime:
        prime_list.append(num)

for num in prime_list[::2]:
    print(num)


1
3
7
13
19
29
37
43
53
61
71
79
89