def slowPrimeDigits(maxValue):
    """ Very slow way to make a list of primes
    Start a list, then remove each number that is a prime times n
    Slow as removing an item from a list means moving every element above it
    """
    # make an array to hold each number up to maxValue
    primes = []
    # fill the array
    for i in range(maxValue):
        primes.append(i)
    # zero and one are not prime
    primes.remove(0)
    primes.remove(1)
    # now apply Sieve of Eratosthenes (google it...)
    for i in primes:
        # make a list of all factors of i (next prime)
        factors = range(i, maxValue, i)
        # first factor is prime (it stays) the rest are removed
        for f in factors[1:]:
            # check if f is still in primes
            if f in primes:
                # if so remove from 
                primes.remove(f)
    # output
    return primes

# set maxmimum value
# for the "slow" code only do up to 10k 
max10k = 10000
sumOfPrimes10k = 5736396

# for fast code can do up to 1M 
max1M = 1000000
sumOfPrimes1M = 37550402023


# timeit runs repeated loops on a line to check how fast it is
# check output is what we expect...

# test new code with
import numpy
if(numpy.sum(slowPrimeDigits(max10k)) != sumOfPrimes10k): 
    print('\nCode failed')
else:
    print('\nCode worked')

# with ipython use "magic" timeit command
print("\nTiming Test with \ntimeit if(numpy.sum(slowPrimeDigits(max10k)) != sumOfPrimes10k): print('Code failed')")

import profile
print("\nProfile the code:\n")
profile.run('out = slowPrimeDigits({})'.format(max10k))