Python Decorator Scoping Issues

I have a static class that has a method hello. I want to run the decorator method bar before hello. However, using the following code I always get a "name 'bar' is not defined" error. Does anyone know what's going on? Thanks!

class foo():
    @staticmethod
    @bar
    def hello():
开发者_StackOverflow        print "hello"

    def bar(fn):
        def wrapped():
            print "bar"
            return fn()
        return wrapped

foo.hello()

Because it's not defined yet. Besides, that decorator shouldn't be a method at all.

def bar(fn):
    # ...

class foo(object):
    @staticmethod
    @bar
    def hello():
        # ...

# ...

Also, don't use static methods, unless you really know what you're doing. Make it a free function instead.

You can just change your code to:

def bar(fn):
    def wrapped():
        print "bar"
        return fn()
    return wrapped
class foo():
    @staticmethod
    @bar
    def hello():
        print "hello"
foo.hello()

This happens because you have to define a function before you call it. This is a problem because this:

@bar
def hello():
    print "hello"

is equivalent to:

def hello():
    print "hello"
hello = bar(hello)

So you were trying to call the function before you defined it.