python entry points 例子

xiuxuan

　　pbr的介绍不多， http://ju.outofmemory.cn/entry/156745
　　
　　$ mkdir entry_test; cd entry_test; git init
　　$ mkdir  -p mypackage/api/v1/
　　$ touch mypackage/__init__.py; touch mypackage/api/__init__.py; touch mypackage/api/v1/__init__.py;
　　$ tree mypackage
　　.
├── mypackage
│   ├── api
│   │   ├── __init__.py
│   │   └── v1
│   │       ├── databases.py
│   │       ├── hello.py
│   │       ├── __init__.py
│   ├── __init__.py
├── setup.cfg
└── setup.py

　　$ cat mypackage/api/v1/databases.py



def main():
print "this is databases main"
　　
　　$ cat mypackage/api/v1/hello.py



def main():
print "this is hello main"
　　
　　$ cat  setup.cfg



[metadata]
name = mypackage
version = 12.0.0
summary = Cloud computing fabric controller
[files]
packages =
mypackage
[entry_points]
mypackage.api.v1 =
databases = mypackage.api.v1.databases:main
hello = mypackage.api.v1.hello:main
[wheel]
universal = 1
[pbr]
autodoc_index_modules = 0
warnerrors = true
　　$ cat setup.py



import setuptools
# In python < 2.7.4, a lazy loading of package `pbr` will break
# setuptools if some other modules registered functions in `atexit`.
# solution from: http://bugs.python.org/issue15881#msg170215

setuptools.setup(
name='mypackage',
packages=['mypackage'],
package_dir={'mypackage': 'mypackage'},
setup_requires=['pbr'],
pbr=True,
entry_points={
'mypackage.api.v1':[
'databases=mypackage.api.v1.databases:main',
'hello=mypackage.api.v1.hello:main',
],
}
)
　　
　　调用方法1：
　　令贤的blog介绍 stevedore： http://blog.csdn.net/lynn_kong/article/details/9704413
　　opensatck 社区介绍stevedore   http://docs.openstack.org/developer/stevedore/tutorial/index.html
　　教程：  https://github.com/openstack/stevedore/tree/master/doc/source/tutorial



from stevedore import extension
def test_detect_plugins():
em = extension.ExtensionManager('mypackage.api.v1')
names = sorted(em.names())
print names
em1 = extension.ExtensionManager('mypackage.api.v1')
eps1 = [ext.plugin for ext in em1]  #plugin是被映射的函数，用于调用
em1 = extension.ExtensionManager('mypackage.api.v1')
eps1 = [ext.entry_point for ext in em1]
　　调用方法2：



import pkg_resources
def run_entry_point(*argv):
group = 'mypackage.api.v1'
for entrypoint in pkg_resources.iter_entry_points(group=group):
# Grab the function that is the actual plugin.
plugin = entrypoint.load()
print plugin
type(plugin)
plugin(*argv)
　　
　　调用方法3：



from pkg_resources import load_entry_point
load_entry_point('mypackage', 'mypackage.api.v1', 'database')()
　　
　　在我的test 例子中需要导入pbr 才能工作，否则有些源代码打包不了。
　　http://blog.oddbit.com/2014/09/27/integrating-custom-code-with-n/
　　https://github.com/larsks/demo_nova_hooks
　　没有导入pbr， 也可以, 需要研究。