Python tarfile progress output?

Question

Hello,

I'm using the following code to extract a tar file:

import tarfile
tar = tarfile.open("sample.tar.gz")
tar.extractall()
tar.close()

However, I'd like to keep tabs on the progress in the form of which files are being extracted at the moment. How can I do this?

EXTRA BONUS POINTS: is it possible to create a percentage of the extraction process as well? I'd like to use that for tkinter to update a progress bar. Thanks!

Answer 1

You could use extract instead of extractall - you would be able to print the member names as they are being extracted. To get a list of members, you could use getmembers.

A textual progressbar library can be found here:

• http://code.google.com/p/python-progressbar/

Tkinter snippet:

• http://tkinter.unpythonic.net/wiki/ProgressBar

Answer 2

def on_progress(filename, position, total_size):
    print "%s: %d of %s" %(filename, position, total_size)

class MyFileObject(tarfile.ExFileObject):
  def read(self, size, *args):
      on_progress(self.name, self.position, self.size)
      return tarfile.ExFileObject.read(self, size, *args)

tarfile.TarFile.fileobject = MyFileObject

Check the tarfile.py module code for more details, the standard library is pretty well written and less scary than you would think.

Edit1: removed monkey-patching (or is this still monkey-patching?), it turns out you can set your own file object.

Edit2: To get an overall byte progress, use the the fileobj argument:

total_size = os.path.getsize("a.tgz")

class MyFileObj(file):
    def read(self, size):
        print "%d of %d" %(self.tell(), total_size)
        return file.read(self, size)

tar = tarfile.open(fileobj=MyFileObj("a.tgz"))
tar.extractall()
tar.close()