arlib 0.0.4

Common interface for archive manipulation

arlib: Common interface for archive manipulation (Tar, Zip, etc)

Table of Contents

• Installation
  • Install from PyPI
  • Install from Anaconda
• Simple example
  • Open archive
  • List member names
  • Open a member
  • License
• Documentation

Rationale

Sometimes, we need to deal with different archive files. There are several packages/modules for archive file manipulation, e.g., zipfile for "*.zip" files, tarfile for "*.tar.gz" or "*.tar.bz2" files, etc. If we want to support different archive type in our project, probably we need to do the following:

if zipfile.is_zipfile(file):
    ar = zipfile.ZipFile(file)
    f = ar.open('member-name')
    # some processing
elif zipfile.is_tarfile(file):
    ar = tarfile.open(file)
    f = ar.extractfile('member-name')
    # some processing
else:
    # other stuffs

The problems of the above approach are:

• We need repeat the above code everywhere we want to support different archive types.
• Different archive manipulation modules (e.g. zipfile and tarfile) may have different API convention.

arlib is designed to solve the above problems. It abstracts the logic of archive manipulations and provides a single high level interface for users.

Installation

Install from PyPI

pip install arlib

Install from Anaconda

conda install -c liyugong arlib

Simple example

The abstract class arlib.Archive defines the common interface to handle different archive types, such as tar file, zip file or an directory. Three concrete classes arlib.TarArchive, arlib.ZipArchive and arlib.DirArchive implement the interface correspondingly.

Open archive

The simplest way to open an archive is using arlib.open function

ar = arlib.open('abc.tar.gz', 'r')

This will determine the type of the archive automatically and return a corresponding object of one of the three engine classes. If we don't want the automatic engine determination mechanism, we can also specify the class via argument engine, e.g.

ar = arlib.open('abc.tar.gz', 'r', engine=ZipArchive)

or we can simply construct an object of the engine class

ar = arlib.ZipArchive('abc.tar.gz', 'r')

List member names

The property member_names will return a list of the names of members contained in the archive, e.g.,

print(ar.member_names)

Check member

Use the method member_is_dir and member_is_file to check whether a member is a directory or a regular file

ar = arlib.open('abc.tar', 'r')
ar.member_is_dir('member_name')
ar.member_is_file('member_name')

Open a member

Use the method open_member to open a member in the archive as a file object

with ar.open_member('a.txt', 'r') as f:
    # do sth by using f as an opened file object

Extract members to a location

Use the method extract to extract members to a specified location

ar = arlib.open('abc.tar', 'r')
ar.extract() # extract all the members to the current working directory
ar.extract(path='d:/hello', members=['abc.txt', 'dir1/'])

License

The arlib package is released under the MIT License

Documentation

https://arlib.readthedocs.io