def netstring(fObj, *strings):
    for s in strings:
        fObj.write('%d:%s\n' % (len(s), s))

def netstringparser(netstrings):
    if netstrings.startswith('\r\n'):
        netstrings = netstrings.replace('\r\n', '\n')
    position = 1
    while True:
        lengthEnd = netstrings.find(':', position)
        if lengthEnd == -1:
            break
        length = int(netstrings[position:lengthEnd])
        yield netstrings[lengthEnd + 1:lengthEnd + 1 + length]
        position = lengthEnd + length + 2