fun.py

#from math import floor
#
#LIMIT = 1000
#
#prime_list = []
#list_primes2 = [True for x in range(LIMIT)]
#list_primes2[0], list_primes2[1] = False, False
#
#for index, value in enumerate(list_primes2):
#    if value:
#        for x in range(index*2, LIMIT, index):
#            list_primes2[x] = False
#
#        prime_list.append(index)
#
#print(prime_list)
##for i, is_prime in enumerate(list_primes2):
##   print(i, is_prime)
#
#from math import floor
#
#prime_list = []
#list_primes2 = [True for x in range(1000)]
#list_primes2[0], list_primes2[1] = False, False
#
#for index, value in enumerate(list_primes2):
#    if value:
#        for x in range(floor(999/index)+1):
#            list_primes2[index*x] = False
#
#        prime_list.append(index)
#
#print(prime_list)
#
# Your problem is that you're either unclear on how the sieve is
# *supposed* to work, or how range really works. You can see that
# if you print out your list that you're using to track whether or
# not a number is prime:

from math import floor

LIMIT = 10
prime_list = []

# I've renamed it to `is_prime`, because that's what we're tracking
is_prime = [True for x in range(LIMIT)]
is_prime[0], is_prime[1] = False, False

for index, value in enumerate(is_prime):
    if value:
        for x in range(floor(LIMIT/index)):
            print(f'Marking {index*x} as not prime')
            is_prime[index*x] = False

        print()
        prime_list.append(index)

for num, is_prime in enumerate(is_prime):
    print(num, 'is prime?', is_prime)

# Outputs:
# 0 is prime? False
# 1 is prime? False
# 2 is prime? False
# 3 is prime? False
# 4 is prime? False
# 5 is prime? False
# 6 is prime? False
# 7 is prime? True
# 8 is prime? False
# 9 is prime? True

# We can see why that's happening if we show what's going on inside this
# loop:

#        for x in range(floor(LIMIT/index)):
#            print(f'Marking {index*x} as not prime')
#            is_prime[index*x] = False