'NoneType' object is not callable

'NoneType' object is not callable when I run the following code


def privilege(min_clearance):
if NAKED not in argv:
def wrapper(argfunc):
def clearancecheck(tag, *args):
if tag.clearance < min_clearance:
global log_file
if log_file != None :
log_file.write(stack().pop()+ " with clearance " + str(tag.clearance) + "called" + \
argfunc.__name__ + "with min clearance" + \
str(min_clearance )+ '\n')
raise SecurityBreach(min_clearance, tag.clearance)
else:
return argfunc
else:
def wrapper(argfunc):
return argfunc
return wrapper

Thank you for your help.

Do you intend this program?
What is argfunc ?
What is the purpose of clearancecheck ? It is difficult to access.
What is NAKED ?
What is the context?
What is the command line?
What is argv ?
What version of python do you use?

Yes, this interactive python console snippet raises an exception:
>>> None()