[Python-Dev] Stackless Python - Pros and Cons (original) (raw)

Gordon McMillan gmcm@hypernet.com
Sun, 6 Aug 2000 19:34:44 -0400

Jack Jansen wrote:

Could the defenders of Stackless Python please explain why this is such a great idea? Just and Christian seem to swear by it, but I'd like to hear of some simple examples of programming tasks that will be programmable in 50% less code with it (or 50% more understandable code, for that matter).

Here's the complete code for the download of a file (the data connection of an FTP server):

def _doDnStream(self, binary=0):
    mode = 'r'
    if binary:
        mode = mode + 'b'
    f = open(self.cmdconn.filename, mode)
    if self.cmdconn.filepos:
        #XXX check length of file
        f.seek(self.cmdconn.filepos, 0)
    while 1:
        if self.abort:
            break
        data = f.read(8192)
        sz = len(data)
        if sz:
            if not binary:
                data = '\r\n'.join(data.split('\n'))
            self.write(data)
        if sz < 8192:
            break

[from the base class] def write(self, msg): while msg: sent = self.dispatcher.write(self.sock, msg) if sent == 0: raise IOError, "unexpected EOF" msg = msg[sent:]

Looks like blocking sockets, right? Wrong. That's a fully multiplexed socket. About a dozen lines of code (hidden in that dispatcher object) mean that I can write async without using a state machine.

stackless-forever-ly y'rs