Question

I have a simple exception-logging decorator, which is handy for sending myself emails when my scripts throw exceptions.

def logExceptions(func):
   def wrapper():
      try:
         func()
      except Exception, e:
         logger.exception(e)

   return wrapper

However, if I want to decorate a class method, I have to modify wrapper() to take a ‘self’, otherwise I get the following error:

TypeError: wrapper() takes no arguments (1 given)

Of course, at that point I can’t use it to decorate any non-class methods, because then this error occurs:

TypeError: wrapper() takes exactly 1 argument (0 given)

Is there a clean way to tackle this problem? Thank you =)

Answer 1

The usual thing is to define your wrapper so it accepts *args and **kwargs and passes them on to the function it wraps. This way it can wrap any function.

Also, I get the impression that what you are calling a “class method” is what Python calls an “instance method”, and what you call “non-class method” is what Python calls a “function”. A “non-class method” (e.g., instance method) in Python takes a self argument.