Project Euler #10 (Python)

Question

Why is my algorithm for finding the sum of all prime numbers below 2 million so slow? I\'m a fairly beginner programmer and this is what I came up with for finding the solution:

Answer 1

There are many optimisations that you could do (and should do since you will need prime generation for many of the problems in project Euler, so having a fast implementation simplifies things later on).

Take a look at the sieve of Atkin (and related sieves) (http://en.wikipedia.org/wiki/Sieve_of_Atkin) to get an understanding of how prime generation can be speeded up over brute force (algorithmically that is).

Then take a look at the awesome answer to this S.O.-post (Fastest way to list all primes below N) that clocks a number of prime generation algorithms/implementations.