How to get an upload progress bar for urllib2?

I currently use the following code to upload one file to a remote server:

import MultipartPostHandler, urllib2, sys
cookies = cookielib.CookieJar()
opener = urllib2.build_opener(MultipartPostHandler.MultipartPostHandler)
params = {"data" : open("foo.bar") }
request=opener.open("http://127.0.0.1/api.php", params)
response = request.read()

This works fine, but for larger files the upload takes some time, and it would be nice to have a callback that allows me to display the upload progress?

I already tried the kodakloader solution, but it does not has a callback for a single file.

Does anyone knows 开发者_如何学Ca solution?

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Here's a snippet from our python dependency script that Chris Phillips and I worked on @ Cogi (though he did this particular portion of it). Complete script is here.

    try:
        tmpfilehandle, tmpfilename = tempfile.mkstemp()
        with os.fdopen(tmpfilehandle, 'w+b') as tmpfile:
            print '  Downloading from %s' % self.alternateUrl

            self.progressLine = ''
            def showProgress(bytesSoFar, totalBytes):
                if self.progressLine:
                    sys.stdout.write('\b' * len(self.progressLine))

                self.progressLine = '    %s/%s (%0.2f%%)' % (bytesSoFar, totalBytes, float(bytesSoFar) / totalBytes * 100)
                sys.stdout.write(self.progressLine)

            urlfile = urllib2.urlopen(self.alternateUrl)
            totalBytes = int(urlfile.info().getheader('Content-Length').strip())
            bytesSoFar = 0

            showProgress(bytesSoFar, totalBytes)

            while True:
                readBytes = urlfile.read(1024 * 100)
                bytesSoFar += len(readBytes)

                if not readBytes:
                    break

                tmpfile.write(readBytes)
                showProgress(bytesSoFar, totalBytes)

    except HTTPError, e:
        sys.stderr.write('Unable to fetch URL: %s\n' % self.alternateUrl)
        raise

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I think it's impossible to know upload progress with urllib2. I'm looking into using pycurl.