changing local namespace of a function

[Kent Johnson]

Bo Peng wrote:
>> Exec is slow since compiling the string and calls to globals() use a 
>> lot of time.  The last one is most elegant but __getattr__ and 
>> __setattr__ are costly. The 'evil hack' solution is good since 
>> accessing x and y takes no additional time.
> 
> 
> Previous comparison was not completely fair since I could pre-compile 
> fun2 and I used indirect __setattr__. Here is the new one:
>  >>> # solution two: use exec
> ... def makeFunction(funcStr, name):
> ...   code = compile(funcStr, name, 'exec')
> ...   def f(d):
> ...     exec code in d
> ...   return f
> ...
>  >>> def fun2(d):
> ...   myfun = makeFunction('z = x + y', 'myfun')
> ...   for i in xrange(0,N):
> ...     myfun(d)
> ...   del d['__builtins__']

You are still including the compile overhead in fun2. If you want to see how fast the compiled code 
is you should take the definition of myfun out of fun2:

myfun = makeFunction('z = x + y', 'myfun')
def fun2(d):
   for i in xrange(0,N):
     myfun(d)
   del d['__builtins__']

Kent