Project Euler Problem 7

The problem:

"By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.

What is the 10 001st prime number?"

Time to make a for loop that checks if a number is a prime or not.With this code, I seem to be able to calculate prime numbers in a correct way. The problem is that it is incredibly slow.

t = 0listOfPrimes = [2]
print("length", len(listOfPrimes))
for numerator in range(3, 200000, 2):
    for x in range(2, numerator):
        if numerator % x != 0:
            for y in range(0, len(listOfPrimes)):
                if numerator % listOfPrimes[y] == 0:
                    t += 1            if t == 0:
                listOfPrimes.append(numerator)
                break            else:
                t = 0    print(len(listOfPrimes))
    if len(listOfPrimes) == 10001:
        break

print("prime no 10001: ", listOfPrimes[10000])

I'm going to rearrange is order of the for-loops to increase the speed of calculation. This didn't make it faster... Now I'm going to try to see if I can limit the modulus checks even more. I've read something somewhere about prime numbers are not dividable by 2 (except the prime number 2) or by any prime numbers that are smaller than the square of the number the is being checked. Wow, I've made a huge miss. I though 10001 was one hundred thousand and one instead of ten thousand and one. Well well, here is my code for finding the 10001th prime:

t = 0listOfPrimes = [2]
for numerator in range(3, 200000, 2):
    if numerator % 2 != 0:
        for x in range(0, len(listOfPrimes)):
            if numerator % listOfPrimes[x] == 0:
                t += 1        if t == 0:
            listOfPrimes.append(numerator)
        else:
            t = 0    print(len(listOfPrimes), numerator)
    if len(listOfPrimes) == 10001:
        break
print("10001th prime: ", listOfPrimes[10000])

I'd like to have a feature in PyCharm that shows the time it took to run an algorithm.

/Ludvig