I'm trying to code a function that finds prime numbers. Some of the "for" loops that I included in the code don't seem to be working

Question

I have been learning how to code with Python for more or less two or three weeks and I came across an exercise that required me to find the number of primes numbers that exist up to a given number. If anyone could help that would be great.

My code seems to be working for the first few prime numbers (it excludes from the list created 4 and 6) but then it stops.

I am new to coding, so this could be wrong, but I think that for some reason one, or even both, of the "for" loops stopped working.

This is my code:

def count_primes(num):
    primes = [2, 3]
    for i in range(4,num+1):
        cond = True
        for x in range(0,len(primes)-1):
            if i%primes[x] == 0:
                cond = False
            elif i%primes[x] > 0:
                    cond = True
        if cond == True:
            primes.append(i)
            pass
    
    print(primes)
    return len(primes)

count_primes(100)