require is a framework for module definitions.

== Overview == It allows to publish dependencies. A function can be decorated to require dependencies by its name.

== Usage == A requirement must be exported using the @export(...) decorator. The decorated function will be called on the first time it is required and the result is cached for later use. It's also possible to decorated a class or anything else which is callable.

To require a dependency the @require(...) decorator can be used. This decorator expects a mapping between parameter names and dependencies. If the decorated function is called, the requirements are resolved and the returned values are passed to the decorated function. The parameter name used to pass the resolved requirements are the same names as used to specify the requirements.

It is possible to extend and manipulate an export using the @extend(...) decorator. After calling the exported function, the return value is passed to all defined extends for this dependency. The extend function can manipulate the object or replace it with another one.

== Example == file: example/foo.py

from require import export

@export() def my_export():

This function will be called on first requirement

return 'exported object'

file: example/bar.py

from require import extend

@extend('example.foo:my_export') def extend_my_export(my_export):

The passed parameter is the result of the required function

If the extend function returns a new value, the export is replaced by it

return 'extended and ' + my_export

file: example/baz.py

from require import require

@require(my_fancy_export = 'example.foo:my_export') def my_user(my_fancy_export):

Parameter 'my_fancy_export' must match the name in the decorator

This will print 'extended and exported object'

print(my_fancy_export)