generator in Python generating prime numbers

Question

I need to generate prime numbers using generator in Python. Here is my code:

def genPrimes():
    yield 2
    x=2
    while True:
        x+=1
        for p in genPrimes():
            if (x%p)==0:
                break
        else:
            yield x

I have a RuntimeError: maximum recursion depth exceeded after the 2nd prime.next() when I run it.

Answer 1

genPrimes() unconditionally calls itself with exactly the same arguments. This leads to infinite recursion.

Here is one way to do it using a (non-recursive) generator:

def gen_primes():
    n = 2
    primes = set()
    while True:
        for p in primes:
            if n % p == 0:
                break
        else:
            primes.add(n)
            yield n
        n += 1

Note that this is optimized for simplicity and clarity rather than performance.