Python的egg包

1、背景

查看flower的源码，首先看到flower的主程序如下：

#!/usr/local/sinasrv2/bin/python2.7
# EASY-INSTALL-ENTRY-SCRIPT: 'flower==0.7.3','console_scripts','flower'
__requires__ = 'flower==0.7.3'
import sys
from pkg_resources import load_entry_point
 
if __name__ == '__main__':
    sys.exit(
        load_entry_point('flower==0.7.3', 'console_scripts', 'flower')()

load_entry_point，它的信息来源是entry_points.txt

entry_points.txt来源呢？

setup.py里面有entry_points 信息,会根据这些信息生成egg info目录,里面有entry_points.txt文件, 里面的内容就是setup.py里的entry_points信息

setup(
    name='flower',
    version=get_package_version(),
    description='Celery Flower',
    long_description=open('README.rst').read(),
    author='Mher Movsisyan',
    author_email='mher.movsisyan@gmail.com',
    url='https://github.com/mher/flower',
    license='BSD',
    classifiers=classifiers,
    packages=find_packages(exclude=['tests', 'tests.*']),
    install_requires=install_requires,
    test_suite="tests",
    tests_require=get_requirements('test.txt'),
    package_data={'flower': ['templates/*', 'static/**/*', 'static/*.*']},
    entry_points={
        'console_scripts': [
            'flower = flower.__main__:main',
        ],
        'celery.commands': [
            'flower = flower.command:FlowerCommand',
        ],
    },
)

　　

然后将封装一个python脚本

说明flower脚本实际调用的是：

两种启动方式

[celery.commands]
flower = flower.command:FlowerCommand
 
[console_scripts]
flower = flower.__main__:main

2、如何制作一个egg包以及对应的setup.py如何写呢？

2.1制作一个空的egg包目录以及setup.py文件

首先建立工程目录egg-demo,初始化一个setup.py文件：

[root@typhoeus79 ice_test_m 20141022]# tree -l
.
`-- egg-demo
    `-- setup.py
 
1 directory, 1 file
[root@typhoeus79 ice_test_m 20141022]# more ./egg-demo/setup.py
#!/usr/bin/env python
#-*- coding:utf-8 -*-
 
from setuptools import setup
 
setup()

写到这里，一个空的egg配置文件就写好了。

setup的帮助文档：

Help on function setup in module distutils.core:
 
setup(**attrs)
    The gateway to the Distutils: do everything your setup script needs
    to do, in a highly flexible and user-driven way.  Briefly: create a
    Distribution instance; find and parse config files; parse the command
    line; run each Distutils command found there, customized by the options
    supplied to 'setup()' (as keyword arguments), in config files, and on
    the command line.
 
    The Distribution instance might be an instance of a class supplied via
    the 'distclass' keyword argument to 'setup'; if no such class is
    supplied, then the Distribution class (in dist.py) is instantiated.
    All other arguments to 'setup' (except for 'cmdclass') are used to set
    attributes of the Distribution instance.
 
    The 'cmdclass' argument, if supplied, is a dictionary mapping command
    names to command classes.  Each command encountered on the command line
    will be turned into a command class, which is in turn instantiated; any
    class found in 'cmdclass' is used in place of the default, which is
    (for command 'foo_bar') class 'foo_bar' in module
    'distutils.command.foo_bar'.  The command class must provide a
    'user_options' attribute which is a list of option specifiers for
    'distutils.fancy_getopt'.  Any command-line options between the current
    and the next command are used to set attributes of the current command
    object.
 
    When the entire command-line has been successfully parsed, calls the
    'run()' method on each command object in turn.  This method will be
    driven entirely by the Distribution object (which each command object
    has a reference to, thanks to its constructor), and the
    command-specific options that became attributes of each command
    object.

setuptools的帮助文档：

Help on package setuptools:
 
NAME
    setuptools - Extensions to the 'distutils' for large or complex distributions
 
FILE
    /usr/local/sinasrv2/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg/setuptools/__init__.py
 
PACKAGE CONTENTS
    archive_util
    command (package)
    depends
    dist
    extension
    package_index
    sandbox
    script template
    script template (dev)
    tests (package)

　　

2.2执行命令生成egg包

python setup.py bdist_egg

setup.py可以支持很多命令：

[root@typhoeus79 ice_test_m egg-demo]# python setup.py --help-commands
Standard commands:
  build             build everything needed to install
  build_py          "build" pure Python modules (copy to build directory)
  build_ext         build C/C++ extensions (compile/link to build directory)
  build_clib        build C/C++ libraries used by Python extensions
  build_scripts     "build" scripts (copy and fixup #! line)
  clean             clean up temporary files from 'build' command
  install           install everything from build directory
  install_lib       install all Python modules (extensions and pure Python)
  install_headers   install C/C++ header files
  install_scripts   install scripts (Python or otherwise)
  install_data      install data files
  sdist             create a source distribution (tarball, zip file, etc.)
  register          register the distribution with the Python package index
  bdist             create a built (binary) distribution
  bdist_dumb        create a "dumb" built distribution
  bdist_rpm         create an RPM distribution
  bdist_wininst     create an executable installer for MS Windows
  upload            upload binary package to PyPI
 
Extra commands:
  saveopts          save supplied options to setup.cfg or other config file
  compile_catalog   compile message catalogs to binary MO files
  develop           install package in 'development mode'
  easy_install      Find/get/install Python packages
  init_catalog      create a new catalog based on a POT file
  test              run unit tests after in-place build
  update_catalog    update message catalogs from a POT file
  setopt            set an option in setup.cfg or another config file
  install_egg_info  Install an .egg-info directory for the package
  rotate            delete older distributions, keeping N newest files
  egg_info          create a distribution's .egg-info directory
  alias             define a shortcut to invoke one or more commands
  extract_messages  extract localizable strings from the project code
  bdist_egg         create an "egg" distribution

　　

输出日志为：

[root@typhoeus79 ice_test_m egg-demo]# python setup.py bdist_egg
running bdist_egg
running egg_info
creating UNKNOWN.egg-info
writing UNKNOWN.egg-info/PKG-INFO
writing top-level names to UNKNOWN.egg-info/top_level.txt
writing dependency_links to UNKNOWN.egg-info/dependency_links.txt
writing manifest file 'UNKNOWN.egg-info/SOURCES.txt'
reading manifest file 'UNKNOWN.egg-info/SOURCES.txt'
writing manifest file 'UNKNOWN.egg-info/SOURCES.txt'
installing library code to build/bdist.linux-x86_64/egg
running install_lib
warning: install_lib: 'build/lib' does not exist -- no Python modules to install
creating build
creating build/bdist.linux-x86_64
creating build/bdist.linux-x86_64/egg
creating build/bdist.linux-x86_64/egg/EGG-INFO
copying UNKNOWN.egg-info/PKG-INFO -> build/bdist.linux-x86_64/egg/EGG-INFO
copying UNKNOWN.egg-info/SOURCES.txt -> build/bdist.linux-x86_64/egg/EGG-INFO
copying UNKNOWN.egg-info/dependency_links.txt -> build/bdist.linux-x86_64/egg/EGG-INFO
copying UNKNOWN.egg-info/top_level.txt -> build/bdist.linux-x86_64/egg/EGG-INFO
zip_safe flag not set; analyzing archive contents...
creating dist
creating 'dist/UNKNOWN-0.0.0-py2.6.egg' and adding 'build/bdist.linux-x86_64/egg' to it
removing 'build/bdist.linux-x86_64/egg' (and everything under it)

再次查看egg-demo目录：

[root@typhoeus79 ice_test_m egg-demo]# tree
.
|-- UNKNOWN.egg-info
|   |-- PKG-INFO
|   |-- SOURCES.txt
|   |-- dependency_links.txt
|   `-- top_level.txt
|-- build
|   `-- bdist.linux-x86_64
|-- dist
|   `-- UNKNOWN-0.0.0-py2.6.egg
`-- setup.py

在dist文件夹下，有一个egg文件：UNKNOWN-0.0.0-py2.6.egg,这说明产蛋成功！

dist/
`-- UNKNOWN-0.0.0-py2.6.egg

　　

egg文件是什么格式的呢？

[root@typhoeus79 ice_test_m dist]# file UNKNOWN-0.0.0-py2.6.egg
UNKNOWN-0.0.0-py2.6.egg: Zip archive data, at least v2.0 to extract

就是一个zip压缩包!看看其内部的结构

[root@typhoeus79 ice_test_m dist]# unzip UNKNOWN-0.0.0-py2.6.egg
Archive:  UNKNOWN-0.0.0-py2.6.egg
  inflating: EGG-INFO/zip-safe
  inflating: EGG-INFO/top_level.txt
  inflating: EGG-INFO/dependency_links.txt
  inflating: EGG-INFO/PKG-INFO
  inflating: EGG-INFO/SOURCES.txt
[root@typhoeus79 ice_test_m dist]# tree ./EGG-INFO/
./EGG-INFO/
|-- PKG-INFO
|-- SOURCES.txt
|-- dependency_links.txt
|-- top_level.txt
`-- zip-safe

只有一个EGG-INFO文件夹，内含五个egg信息文件。

这个egg名称未知，版本0.0.0。这是因为我们在setup里什么也没有设置。

显然，这个egg什么也不能做。

2.3 在egg包增加新功能-制作demo package

在setup.py中，setup函数接收一系列属性作为配置参数。

• name name是egg包的名称，也是寻找要打包的文件夹的名称，默认是UNKNOWN。
• version 版本号，默认0.0.0
• packages 这里要用到setuptools的另一个函数find_packages，顾名思义，find_packages用来将指定目录下的文件打包。
• zip_safe 默认是False，这样在每次生成egg包时都会检查项目文件的内容，确保无误。

还有一些描述性的属性，如description，long_description，author，author_email，license，keywords，platform，url等。

[root@typhoeus79 ice_test_m egg-demo]# more setup.py
#!/usr/bin/env python
#-*- coding:utf-8 -*-
 
from setuptools import setup, find_packages
 
setup(
        name = "demo",
        version="0.1.0",
        packages = find_packages(),
        zip_safe = False,
 
        description = "egg test demo.",
        long_description = "egg test demo, haha.",
        author = "amoblin",
        author_email = "amoblin@ossxp.com",
 
        license = "GPL",
        keywords = ("test", "egg"),
        platforms = "Independant",
        url = "",
        )

在egg-demo目录下建立和上述name名称相同的目录demo，demo目录下写__init__.py文件：

 

[root@typhoeus79 ice_test_m egg-demo]# tree ./demo/
./demo/
`-- __init__.py
 
0 directories, 1 file
[root@typhoeus79 ice_test_m egg-demo]# more ./demo/__init__.py
#!/usr/bin/env python
#-*- coding:utf-8 -*-
 
def test():
    print "Hello, I'm amoblin."
 
if __name__ == '__main__':
    test()

　　

再次生成egg包以后查看egg包信息：

[root@typhoeus79 ice_test_m egg-demo]# ll
总计 20
drwxr-xr-x 4 root root 4096 10-22 14:34 build
drwxr-xr-x 2 root root 4096 10-22 14:33 demo
drwxr-xr-x 2 root root 4096 10-22 14:34 demo.egg-info
drwxr-xr-x 2 root root 4096 10-22 14:34 dist
-rw-r--r-- 1 root root  496 10-22 14:31 setup.py

　

新的egg包里面的信息如下：

[root@typhoeus79 ice_test_m dist]# unzip demo-0.1.0-py2.6.egg
Archive:  demo-0.1.0-py2.6.egg
  inflating: EGG-INFO/not-zip-safe
  inflating: EGG-INFO/top_level.txt
  inflating: EGG-INFO/dependency_links.txt
  inflating: EGG-INFO/PKG-INFO
  inflating: EGG-INFO/SOURCES.txt
  inflating: demo/__init__.pyc
  inflating: demo/__init__.py

　　

现在可以安装了体验一下！！

[root@typhoeus79 ice_test_m egg-demo]# python setup.py install
running install
running bdist_egg
running egg_info
writing demo.egg-info/PKG-INFO
writing top-level names to demo.egg-info/top_level.txt
writing dependency_links to demo.egg-info/dependency_links.txt
reading manifest file 'demo.egg-info/SOURCES.txt'
writing manifest file 'demo.egg-info/SOURCES.txt'
installing library code to build/bdist.linux-x86_64/egg
running install_lib
running build_py
creating build/bdist.linux-x86_64/egg
creating build/bdist.linux-x86_64/egg/demo
copying build/lib/demo/__init__.py -> build/bdist.linux-x86_64/egg/demo
byte-compiling build/bdist.linux-x86_64/egg/demo/__init__.py to __init__.pyc
creating build/bdist.linux-x86_64/egg/EGG-INFO
copying demo.egg-info/PKG-INFO -> build/bdist.linux-x86_64/egg/EGG-INFO
copying demo.egg-info/SOURCES.txt -> build/bdist.linux-x86_64/egg/EGG-INFO
copying demo.egg-info/dependency_links.txt -> build/bdist.linux-x86_64/egg/EGG-INFO
copying demo.egg-info/not-zip-safe -> build/bdist.linux-x86_64/egg/EGG-INFO
copying demo.egg-info/top_level.txt -> build/bdist.linux-x86_64/egg/EGG-INFO
creating 'dist/demo-0.1.0-py2.6.egg' and adding 'build/bdist.linux-x86_64/egg' to it
removing 'build/bdist.linux-x86_64/egg' (and everything under it)
Processing demo-0.1.0-py2.6.egg
creating /usr/lib/python2.6/site-packages/demo-0.1.0-py2.6.egg
Extracting demo-0.1.0-py2.6.egg to /usr/lib/python2.6/site-packages
Adding demo 0.1.0 to easy-install.pth file
 
Installed /usr/lib/python2.6/site-packages/demo-0.1.0-py2.6.egg
Processing dependencies for demo==0.1.0
Finished processing dependencies for demo==0.1.0

　　

安装完毕！接下来我们就可以直接通过import来使用啦！

>>> from demo import test
>>> help(test)
 
>>> test()
Hello, I'm amoblin.

　　

源程序都放在src目录下，所以接下来将demo文件夹移动到src里。但这样也要修改setup.py文件，修改find_packages函数中参数为’src’，同时增加package_dir参数：

packages=find_packages('src'),
package_dir = {'':'src'}

这样告诉setuptools在src目录下找包，而不是原来默认的工程根目录。

2.4如何删除egg包

找到package放的位置

>>> print sys.path[1]
/usr/lib/python2.6/site-packages/setuptools-0.6c11-py2.6.egg

存在这个egg包　　

[root@typhoeus79 ice_test_m site-packages]# ll /usr/lib/python2.6/site-packages |grep demo
drwxr-xr-x 4 root root   4096 10-22 14:36 demo-0.1.0-py2.6.egg
[root@typhoeus79 ice_test_m site-packages]# cat easy-install.pth|grep demo
./demo-0.1.0-py2.6.egg

　　

卸载egg文件很简单，首先将包含此egg的行从easy-install.pth中删除，然后删除egg文件夹即可。

3、参考资料

1、http://www.cnblogs.com/itech/archive/2011/02/13/1953268.html

2、http://zhiwei.li/text/2011/06/load_entry_point%E5%92%8Csetup-egg/

3、http://django-china.cn/topic/90/

4、http://blog.habnab.it/blog/2013/07/21/python-packages-and-you/