Acts as a proxy for a werkzeug local. Forwards all operations to
a proxied object. The only operations not supported for forwarding
are right handed operands and any kind of assignment.
Example usage::
from werkzeug.local import Local
l = Local()
# these are proxies
request = l('request')
user = l('user')
from werkzeug.local import LocalStack
_response_local = LocalStack()
# this is a proxy
response = _response_local()
Whenever something is bound to l.user / l.request the proxy objects
will forward all operations. If no object is bound a :exc:`RuntimeError`
will be raised.
To create proxies to :class:`Local` or :class:`LocalStack` objects,
call the object as shown above. If you want to have a proxy to an
object looked up by a function, you can (as of Werkzeug 0.6.1) pass
a function to the :class:`LocalProxy` constructor::
session = LocalProxy(lambda: get_current_request().session)
.. versionchanged:: 0.6.1
The class can be instantiated with a callable as well now.