PS1a

allprimes = [1, 2, 3]                     # defines a variable as an array of primes
candidate = 5                               # defines a starting candidate
while len(allprimes) < 1000:                # starts a conditional loop under which the following steps will repeat
    for number in allprimes:                # nests another loop -- for each number in the list of primes
        if candidate % number == 0:         # if any number in the array of primes divides evenly into the candidate
            break                           # stop the loop
        else:                               # otherwise
            allprimes.append(candidate)     # append the candidate to the end of the allprimes array
            candidate = candidate + 2       # redefine candidate as its previous value + 2
if len(allprimes) == 1000:                  # when the length of the prime list reaches 1000
    print allprimes[-1]                     # print that last sucker out