Question

I’m using decorator with the functional syntax as it’s described here.

I loop over a list of dict. In this loop I wrap a generic function with a decorator taking a parameter. Then i call the wrapped function with the current dict as parameters.

My problem is that i get an local variable 'generic_evaluator' referenced before assignment error.

Here is my code:

The concerned decorator:

def log(logfile_name):
    def inner_log(func):
        def wrapped(*args, **kwargs):
            import os
            ret = func()
            # business code...
        return wraps(func)(wrapped)
    return inner_log

And here the place where I wrap generic_evaluator function with the log decorator.

for evaluation in generic_evaluations:
    generic_evaluator = log(evaluation['suffix'])(generic_evaluator)
    generic_evaluator(evaluation['suffix'], evaluation['id'])

EDIT

It’ll be probably more clear with this piece of code in addition:

@tictoc
def generic_evaluator(suffix_url, id):
    xml = etree.parse(get_resource(base_url + "/" + suffix_url + "/" + str(id)))
    links = fetch_urls_from_xml(xml)
    return links

Answer 1

If generic_evaluator is a global function, and you actually want to rebind the global name generic_evaluator, declare this name as global:

global generic_evaluator

If you don’t want to rebind the global name, use a different local name and initialise it:

local_generic_evaluator = generic_evaluator

This answer gives an explanation of what’s going on.