eratostenes.py

# Implementation of the sieve of Eratostenes.
# Calculates all the prime numbers in a range up to the specified limit.
import math
import sys

def process(squareRoot, list):
    """This function calculates all the prime numbers in a range (from 2 to the
    limit you specify).
    Takes as arguments:
    squareRoot - the square root of the highest number rounded down
    list - a range(2, limit_number)
    """
    count = 0
    while count <= squareRoot:
        for i in list[count+1:]:
            result = i % list[count]
            if result == 0:
                list.remove(i)
        count = count + 1
    return list

# If the program is directly called, not by another program, then print a list
# of the prime numbers found.
if __name__ == '__main__':
    try:
        limit = int(sys.argv[1])
    except IndexError:
        limit = input('qual o numero limite do calculo a ser feito? ')

    list = range(2,limit)
    squareRoot = int(math.sqrt(limit))
    process(squareRoot, list)
    for item in list:
        print item