Any python scripts to do parallel downloading?

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On Jan 31, 5:23 pm, "Frank Potter" <could.... at gmail.com> wrote:
> I want to find a multithreaded downloading lib in python,
> can someone recommend one for me, please?
> Thanks~

Why do you want to use threads for that? Twisted is the
obvious solution for your problem, but you may use any
asynchronous framework, as for instance the good ol
Tkinter:

"""
Example of asynchronous programming with Tkinter. Download 10 times
the same URL.
"""

import sys, urllib, itertools, Tkinter

URL = 'http://docs.python.org/dev/lib/module-urllib.html'

class Downloader(object):
    chunk = 1024

    def __init__(self, urls, frame):
        self.urls = urls
        self.downloads = [self.download(i) for i in range(len(urls))]
        self.tkvars = []
        self.tklabels = []
        for url in urls:
            var = Tkinter.StringVar(frame)
            lbl = Tkinter.Label(frame, textvar=var)
            lbl.pack()
            self.tkvars.append(var)
            self.tklabels.append(lbl)
        frame.pack()

    def download(self, i):
        src = urllib.urlopen(self.urls[i])
        size = int(src.info()['Content-Length'])
        for block in itertools.count():
            chunk = src.read(self.chunk)
            if not chunk: break
            percent = block * self.chunk * 100/size
            msg = '%s: downloaded %2d%% of %s K' % (
                self.urls[i], percent, size/1024)
            self.tkvars[i].set(msg)
            yield None
        self.tkvars[i].set('Downloaded %s' % self.urls[i])

if __name__ == '__main__':
    root = Tkinter.Tk()
    frame = Tkinter.Frame(root)
    downloader = Downloader([URL] * 10, frame)
    def next(cycle):
        try:
            cycle.next().next()
        except StopIteration:
            pass
        root.after(50, next, cycle)
    root.after(0, next, itertools.cycle(downloader.downloads))
    root.mainloop()


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