Extracts .tar, .tar.gz, .tar.bz2 and .zip files with an optional progress bar. Raises ExtractException when it encounters an error.

extract-progress.py

import os, re, commands, subprocess

def streamCommand(cmd):
    # runs a shell command and returns stdout as a stream you can loop over
    stdout = subprocess.Popen(cmd, shell=True,
                        stdout=subprocess.PIPE,
                        stderr=subprocess.STDOUT).stdout
    return stdout

def getFileExtension(filename):
    # returns the file extension of a file, including archives with two dots
    ext = filename.split('.')

    if ext[-2] == 'tar':
        return "tar." + ext[-1]
    else:
        return ext[-1]

def extractArchive(src, progress=True, dst=False):
    file_type = getFileExtension(src).lower()

    extract_commands = {
        "tar":     "tar -vxf",
        "tar.gz":  "tar -vzxf",
        "tar.bz2": "tar -xvjf",
        "zip":     "unzip -o"
    }

    if file_type in extract_commands:
        # check if we have a command to extract this type of file
        cmd = extract_commands[file_type]
    else:
        # we can't extract this type of file; give up
        raise ExtractException(file_type + " is an unsupported file type.")

    # add filename to the command
    cmd += ' ' + src

    # if destination directory is specified append the necessary flags
    if dst is False:
        # make sure that the path actually exists
        if os.path.exists(dst) is False:
            raise ExtractException("Destination directory %s doesn't exist" % dst)

        if file_type == 'zip':
            cmd += " -d %s" % dst
        else:
            cmd += " -C %s" % dst

    if progress is True:
        # output progress to the terminal
        start_line = "Extracting %s" % os.path.basename(src)

        if dst is True:
            start_line += " to %s" % dst

        print start_line

        # determine number of files in archive
        if file_type != 'zip':
            file_count = commands.getoutput("tar -tf %s | wc -l" % src).strip()
        else:
            file_count = commands.getoutput("unzip -l %s" % src)
            # extracts file count from last line of unzip -l output
            # ex: 196727429                   4395 files
            file_count = re.search('(\d+)\sfiles', file_count).group(1)

        # convert file_count from string to integer
        file_count = int(file_count)

        # stream each line of output from extraction to update progress bar
        extracted = 0

        digit_length = str(len(str(file_count)))
        # determine the number of leading spaces based on the file_count
        
        for line in streamCommand(cmd):
            extracted += 1
            status = "Extracted %" + digit_length + "d files [%3.2f%%]"
            status = status % (extracted, extracted * 100. / file_count)
            status = status + chr(8) * (len(status) + 1)
            print status,

        # reset cursor to the next line
        print("")

        return extracted == file_count
    else:
        # extract without progress, use exit status instead of file count
        # to determine whether extraction was successful
        result = commands.getoutput("unzip -l %s" % src)

        # an error occurred during extraction
        if result[0] > 0:
            raise ExtractException(result[1])
        else:
            return True