Python version assert fails on odd numbers

[martin-niklasson]

Try:
sieve = prime_sieve(999999) # Calc the primes up to a million-1

Result:
assert(count == this.countPrimes()) AssertionError

The reason is that keyword int in Python doesn't do what a C++ programmer thinks:
this.rawbits = [True] * (int((this.sieveSize+1)/2))

Fix by:
from math import sqrt,floor # Used by the sieve
and
this.rawbits = [True] * (floor((this.sieveSize)/2))

[hegdenischay]

Why not just this.rawbits = [True] * ((this.sieveSize)//2))?
I thought it'd be more performant, since it's an operator rather than a function, but I don't see any real performance benefit on my own machine.

[davepl]

Check in a fix, I'll gladly accept!