Script: clean_bzip – a command line program for clean directory compression
A simple command-line python utility that compresses a directory (or directories) and excludes certain unwanted files.
As a self-taught Python user I am still looking for insight on the most pythonic and programmatically-friendly way of accomplishing a given task. In this case, I have written a script that will perform a “clean bzip2” of a directory (or directories). Mac OS X (via AFP and netatalk, in my case) tends leaves a bunch of ugly files/directories hanging around and I would rather not include them in my compressed tar file.
In writing the script, though, I ran into some questions and I am not sure what the recommended approach would be. The script works, as it is, but I feel its a little hacked together and also a little limited in its application. There is something to be said for programs that “just work” (this does) but I want to take it a little further as an educational endeavor and would like it to appear robust, future-thinking, and pythonic.
My initial questions are:
Is there a better way to implement a[using
- I am not very clear on the use of Exceptions (or even if I am using it in a good way here) — is what I have done the right approach?
- Finally, in general: any feedback on how to improve this? (I am thinking, just now, that the script is only suitable for a command line usage, and couldn’t be imported by another script, for example.)
Any feedback is greatly appreciated. Writing a script like this is a good learning tool (for me, at least).
#! /usr/bin/env python '''Script to perform a "clean" bzip2 on a directory (or directories). Removes extraneous files that are created by Apple/AFP/netatalk before compressing. ''' import os import tarfile import logging from optparse import OptionParser # Default files and directories to exclude from the bzip tar IGNORE_DIRS = ('.AppleDouble',) IGNORE_FILES = ('.DS_Store',) class DestinationTarFileExists(Exception): '''If the destination tar.bz2 file already exists.''' def ignore_walk(directory, ignore_dirs=None, ignore_files=None): '''Ignore defined files and directories when doing the walk.''' # TODO: this does not currently take wild cards into account. For example, # if you wanted to exclude *.pyc files ... should fix that. Perhaps # consider moving this entirely into the below function (or making it more # reusable for other apps). for dirpath, dirnames, filenames in os.walk(directory): if ignore_dirs: dirnames[:] = [dn for dn in dirnames if dn not in ignore_dirs] if ignore_files: filenames[:] = [fn for fn in filenames if fn not in ignore_files] yield dirpath, dirnames, filenames def tar_bzip2_directory(directory, ignore_dirs=IGNORE_DIRS, ignore_files=IGNORE_FILES ): '''Takes a directory and creates a tar.bz2 file (based on the directory name). You can exclude files and sub-directories as desired.''' file_name = '-'.join(directory.split(' ')) tar_name = file_name.replace('/','').lower() + ".tar.bz2" if os.path.exists(tar_name): msg = ("The file %s already exists. " + "Please move or rename it and try again.") % tar_name raise DestinationTarFileExists(msg) tar = tarfile.open(tar_name, 'w:bz2') for dirpath, dirnames, filenames in ignore_walk(directory, ignore_dirs, ignore_files): for file in filenames: logging.info(os.path.join(dirpath, file)) tar.add(os.path.join(dirpath, file)) tar.close() def main(args=None, callback=None): directories =  for arg in args: if os.path.isdir(arg): directories.append(arg) else: logging.ERROR("Ingoring: %s (it's not a directory)." % arg) for dir in directories: try: tar_bzip2_directory(dir) except DestinationTarFileExists, e: print e if __name__ == "__main__": parser = OptionParser(usage="%prog [options: -q ] [dir1] [...dir2]") parser.add_option("-q", "--quiet", action="store_true", dest="quiet") options, args = parser.parse_args() if options.quiet: logging.basicConfig(level=logging.ERROR, format='%(message)s') else: logging.basicConfig(level=logging.INFO, format='%(message)s') main(args)