依赖关系

如果你使用Python, 很自然的你会使用其他人在PyPI或者其他地方公开发布的包

setuptools给我们提供了很方便的工具来说明依赖关系, 而且在安装我们的包的时候会自动安装依赖包.

我们可以给 funniest joke 添加一些格式， 使用 Markdown.

__init__.py

from markdown import markdown

def joke():
    return markdown(u'How do you tell HTML from HTML5?'
                    u'Try it out in **Internet Explorer**.'
                    u'Does it work?'
                    u'No?'
                    u'It\'s HTML5.')

现在我们的包依赖 markdown 这个包. 我们需要在 setup.py 中添加 install_requires 参数:

from setuptools import setup

setup(name='funniest',
      version='0.1',
      description='The funniest joke in the world',
      url='http://github.com/storborg/funniest',
      author='Flying Circus',
      author_email='flyingcircus@example.com',
      license='MIT',
      packages=['funniest'],
      install_requires=[
          'markdown',
      ],
      zip_safe=False)

为了测试是否可行，我们可以试一试 python setup.py develop

$ python setup.py develop
running develop
running egg_info
writing requirements to funniest.egg-info/requires.txt
writing funniest.egg-info/PKG-INFO
writing top-level names to funniest.egg-info/top_level.txt
writing dependency_links to funniest.egg-info/dependency_links.txt
reading manifest file 'funniest.egg-info/SOURCES.txt'
writing manifest file 'funniest.egg-info/SOURCES.txt'
running build_ext
Creating /.../site-packages/funniest.egg-link (link to .)
funniest 0.1 is already the active version in easy-install.pth

Installed /Users/scott/local/funniest
Processing dependencies for funniest==0.1
Searching for Markdown==2.1.1
Best match: Markdown 2.1.1
Adding Markdown 2.1.1 to easy-install.pth file

Using /.../site-packages
Finished processing dependencies for funniest==0.1

当我们安装funniest包的时候, pip install funniest 也会同时安装 markdown .

不在PyPI中的包

有时候, 你需要一些按照setuptools格式组织的安装包, 但是它们没有在PyPI发布. 在这种情况下, 你可以在 dependency_links 中填入下载的URL, 可能需要在URL中加一些其他信息, setuptools将根据URL找到和安装这些依赖包.

举个例子, Github上的包可以按照下面的格式填写URL:

setup(
    ...
    dependency_links=['http://github.com/user/repo/tarball/master#egg=package-1.0']
    ...
)