Quickly create flexible Python decorators
Project description
The problem
Python has a few forms for decorators, you can have a plain simple decorator, with no arguments:
@mydecorator
def foo(): pass
Or a decorator with some arguments:
@mydecorator(1, 2)
def foo(): pass
You can even decorate a class:
@mydecorator
class Foo(object): pass
and each form is a little different to implement. This was frustrating if you wanted to create easy to use decorators where the developer didn’t need to worry about @mydecorator() working differently than @mydecorator.
decorators module
The decorators module allows you to easily create broad decorators that encompass all forms and all types (functions, methods, classes) using the same interface:
import decorators
class mydecorator(decorators.Decorator):
def decorate_func(self, func, *dec_args, **dec_kwargs):
def decorator(*args, *kwargs):
print "You passed into the decorator these arguments", dec_args, dec_kwargs
print "You passed into your function these arguments", args, kwargs
print "Your function is", func
return func(*args, **kwargs)
return decorator
def decorate_class(self, klass, *dec_args, **dec_kwargs):
print "You passed into the decorator these arguments", dec_args, dec_kwargs
print "Your class is", klass
return klass
You can then use this decorator:
@mydecorator
def foo(): print "foo()"
@mydecorator(1, 2, boom="blam")
def bar(*args, **kwargs): print "bar()"
@mydecorator
class Baz(object): pass
@mydecorator(1, 2, boom="blam")
class Che(object): pass
Now, your decorator can decorate functions or classes, pass in arguments, or not, and you never have to worry about the subtle differences between the decorators, and best of all, you don’t have to duplicate code.
Other decorators
The Decorator class is good if you want to create a decorator that is totally flexible, if you want to enforce your decorator only being used for a function/method, you can use FuncDecorator. If you want to only decorate a class, use ClassDecorator, and if you want to decorate every instance of a class, use InstanceDecorator.
import decorators
class only_func(FuncDecorator):
def decorate(self, func, *dec_a, **dec_kw):
def decorator(*args, **kwargs):
return func(*args, **kwargs)
return decorator
# this will work
@only_func
def foo(): pass
# this will fail
@only_func
class Foo(object): pass
Installation
Use pip:
pip install decorators
Or, to get the latest and greatest from source:
pip install git+https://github.com/firstopinion/decorators#egg=decorators
License
MIT
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.