I'm trying to write a decorator that causes a function to do nothing
if called more than once- the reason for this is trivial and to see if
I can (Read- I'm enjoying the challenge, please don't ruin it for me
=] )
However I'm getting strange results with Python 2.6.2 on win32.
With this code:
def callonce(func):
def nullmethod(): pass
def __():
return func()
return __
@callonce
def t2():
print "T2 called"
t2()
It does exactly what you'd expect, prints "T2 called"
However:
def callonce(func):
def nullmethod(): pass
def __():
return func()
func = nullmethod
return ret
return __
@callonce
def t2():
print "T2 called"
t2()
Gives me:
C:\tmp\callonce>callonce.py
Traceback (most recent call last):
File "C:\tmp\callonce\callonce.py", line 27, in <module>
t2()
File "C:\tmp\callonce\callonce.py", line 12, in __
return func()
UnboundLocalError: local variable 'func' referenced before assignment
Any ideas on why? This looks like a bug to me, but I'm quite new to
this style of programming so it may be some nuance I'm not aware of.
Thanks in advance.
Rich Healey
--
http://mail.python.org/mailman/listinfo/python-list
