143 lines
4.6 KiB
Plaintext
143 lines
4.6 KiB
Plaintext
PEP: 441
|
||
Title: Improving Python ZIP Application Support
|
||
Version: $Revision$
|
||
Last-Modified: $Date$
|
||
Author: Daniel Holth <dholth@gmail.com>
|
||
Status: Draft
|
||
Type: Standards Track
|
||
Content-Type: text/x-rst
|
||
Created: 30 March 2013
|
||
Post-History: 30 March 2013, 1 April 2013
|
||
|
||
Improving Python ZIP Application Support
|
||
========================================
|
||
|
||
Python has had the ability to execute directories or ZIP-format
|
||
archives as scripts since version 2.6 [1]_. When invoked with a zip
|
||
file or directory as its first argument the interpreter adds that
|
||
directory to sys.path and executes the __main__ module. These
|
||
archives provide a great way to publish software that needs to be
|
||
distributed as a single file script but is complex enough to need to
|
||
be written as a collection of modules.
|
||
|
||
This feature is not as popular as it should be mainly because no one’s
|
||
heard of it as it wasn’t promoted as part of Python 2.6 [2]_, but also
|
||
because Windows users don’t have a file extension (other than .py) to
|
||
associate with the launcher.
|
||
|
||
This PEP proposes to fix these problems by re-publicising the feature,
|
||
defining the .pyz and .pyzw extensions as “Python ZIP Applications”
|
||
and “Windowed Python ZIP Applications”, and providing some simple
|
||
tooling to manage the format.
|
||
|
||
A New Python ZIP Application Extension
|
||
======================================
|
||
|
||
The Python 3.4 installer will associate .pyz and .pyzw “Python ZIP
|
||
Applications” with the platform launcher so they can be executed. A
|
||
.pyz archive is a console application and a .pyzw archive is a
|
||
windowed application, indicating whether the console should appear
|
||
when running the app.
|
||
|
||
Why not use .zip or .py? Users expect a .zip file would be opened with
|
||
an archive tool, and users expect .py to contain text. Both would be
|
||
confusing for this use case.
|
||
|
||
For UNIX users, .pyz applications should be prefixed with a #! line
|
||
pointing to the correct Python interpreter and an optional
|
||
explanation::
|
||
|
||
#!/usr/bin/env python3
|
||
# This is a Python application stored in a ZIP archive, created with
|
||
# pyzaa.
|
||
(binary contents of archive)
|
||
|
||
As background, ZIP archives are defined with a footer containing
|
||
relative offsets from the end of the file. They remain valid when
|
||
concatenated to the end of any other file. This feature is completely
|
||
standard and is how self-extracting ZIP archives and the bdist_wininst
|
||
installer format work.
|
||
|
||
Minimal Tooling: The pyzaa Module
|
||
=================================
|
||
|
||
This PEP also proposes including a simple application for working with
|
||
these archives: The Python Zip Application Archiver “pyzaa” (rhymes
|
||
with “huzzah” or “pizza”). “pyzaa” can archive these files, compile
|
||
bytecode, and can write the __main__ module if it is not present.
|
||
|
||
Usage
|
||
-----
|
||
|
||
``python -m pyzaa (pack | compile)``
|
||
|
||
``python -m pyzaa pack [-o path/name] [-m module.submodule:callable] [-c] [-w]
|
||
[-p interpreter] directory``::
|
||
|
||
ZIP the contents of directory as directory.pyz or [-w]
|
||
directory.pyzw. Adds the executable flag to the archive.
|
||
|
||
``-c`` compile .pyc files and add them to the archive
|
||
|
||
``-p interpreter`` include #!interpreter as the first line of the archive
|
||
|
||
``-o path/name`` archive is written to path/name.pyz[w] instead of
|
||
dirname. The extension is added if not specified.
|
||
|
||
``-m module.submodule:callable`` __main__.py is written as “import
|
||
module.submodule; module.submodule.callable()”
|
||
|
||
pyzaa pack will warn if the directory contains C extensions or if
|
||
it doesn’t contain __main__.py.
|
||
|
||
``python -m pyzaa compile arcname.pyz[w]``::
|
||
|
||
The Python files in arcname.pyz[w] are compiled and appended to the
|
||
ZIP file.
|
||
|
||
A standard ZIP utility or Python’s zipfile module can unpack the
|
||
archives.
|
||
|
||
FAQ
|
||
---
|
||
|
||
Q. Are you sure a standard ZIP utility can handle #! at the beginning?
|
||
|
||
A. Absolutely. If it doesn't, it is a bug in your archive program.
|
||
|
||
Q. Isn’t pyzaa just a very thin wrapper over zipfile and compileall?
|
||
|
||
A. Yes.
|
||
|
||
Q. How does this compete with existing sdist/bdist formats?
|
||
|
||
A. There is some overlap, but .pyz files are especially interesting
|
||
as a way to distribute an installer. They may also prove useful as a
|
||
way to deliver applications when users shouldn’t be asked to perform
|
||
virtualenv + “pip install”.
|
||
|
||
References
|
||
==========
|
||
|
||
.. [1] “Allow interpreter to execute a zip file”
|
||
(http://bugs.python.org/issue1739468)
|
||
|
||
.. [2] “Feature is not documented”
|
||
(http://bugs.python.org/issue17359)
|
||
|
||
Copyright
|
||
=========
|
||
|
||
This document has been placed into the public domain.
|
||
|
||
|
||
|
||
..
|
||
Local Variables:
|
||
mode: indented-text
|
||
indent-tabs-mode: nil
|
||
sentence-end-double-space: t
|
||
fill-column: 70
|
||
coding: utf-8
|
||
End:
|