ObjectProxy
This module provides a way to build lazy proxies to any kind of Python
entity.
Use

Lazy proxy

To make a proxy to a module, instanciate the Proxy class with a string representing the import name of the module as parameter:

from object_proxy.lazy import LazyProxy

path = LazyProxy('os.path')

Only when the proxy is used for the first time, the target module is imported.

To make a proxy to an object or a class, use the colon (:) syntax:

environ = LazyProxy('os:environ')

When the proxy is used, it’s equivalent to:

from os import environ

Note

The functions repr() and id() are not proxied to target.

Context-dependent proxy

The proxy can be context-dependent.

You must instanciate a context:

from object_proxy.lazy import LazyProxy
from object_proxy.context import Context

gevent_context = Context('gevent')
eventlet_context = Context('eventlet')

patch = LazyProxy('gevent.monkey:patch_all', context=gevent_context)
eventlet_context.register(patch, 'eventlet:monkey_patch')

# Run monkey patch from gevent
Context.activate('gevent')
# Or: Context.activate(gevent_context)
# Or: gevent_context.activate()
patch()

# Run monkey patch from eventlet
Context.activate('eventlet')
# Identical to the previous
patch()

You can know whether a proxy belongs to a context using id() and in:

>>> id(patch) in gevent_context
True

To discover which contexts a proxy belongs:

>>> Context.find_proxy(patch)
[('gevent', 'gevent.monkey:patch_all'), ('eventlet', 'eventlet:monkey_patch')]

Contexts can get children:

>>> context = gevent_context.get_child('with_path')
>>> context.name
'gevent.with_path'
>>> path = LazyProxy('os.path', context=context)
>>> context.activate()
>>> path
<module 'posixpath' from '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.pyc'>
>>> patch
<function patch_all at 0x109b1a848>

The function patch() is inherited from super context.

Download and install

ObjectProxy can be downloaded from GitHUB or installed using pip:

pip install ObjectProxy

TODO

There’s a lot work to do. You can mail me with suggestions or see the project issues.

License

ObjectProxy is licensed under BSD New. See LICENSE file.

Author

Rodrigo Cacilhας <batalema@cacilhas.info>