Generating a list of primes of a given length
Don't be afraid of typing. Longer names are more readable and should be used except for simple counters. Split out complicated sub-parts where they are separate concepts.

Here is how I would improve it:

import math

def isPrime (primeList, candidate):
    upperLimit = math.sqrt(candidate)
    for p in primeList:
        if candidate % p == 0:
            return False
        if p &gt;= upperLimit:
            break

    return True

def primeList(listLength):
    if listLength &lt; 1 :
        return []
    primes = [2]

    candidate = 3
    while listLength &gt; len(primes):
        if isPrime(primes, candidate):
            primes.append(candidate)
        candidate +=2

    return primes


To make a faster simple prime algorithm, consider the other naive algorithm in the primality test wikipedia article where all primes are of the form 6k +- 1.