5dollarwhitebox.org - theboxownsyou

def convert_bytes(n):
    K, M, G, T = 1 << 10, 1 << 20, 1 << 30, 1 << 40
    if   n >= T:
        return '%.1fT' % (float(n) / T)
    elif n >= G:
        return '%.1fG' % (float(n) / G)
    elif n >= M:
        return '%.1fM' % (float(n) / M)
    elif n >= K:
        return '%.1fK' % (float(n) / K)
    else:
        return '%d' % n
 
def test_bytes():
    for n in range(15):
        print '%15d %8s' % (10**n, convert_bytes(10**n))