[Numpy-discussion] function name as parameter

[Johann Cohen-Tanugi]

On 10/20/2010 10:35 PM, Nathaniel Smith wrote:
> On Wed, Oct 20, 2010 at 6:51 AM, Johann Cohen-Tanugi
> <cohen at lpta.in2p3.fr>  wrote:
>    
>> If you really need to pass the function name :
>> In [3]: def my_func(x):
>>     ...:     return 2*x
>>
>> In [4]: def caller(fname,x):
>>     ...:     return eval("%s(%f)"%(fname,x))
>>
>> In [5]: caller("my_func",2)
>> Out[5]: 4.0
>>      
> The better way to do this is:
>
> import inspect
> def call_this(fname, x):
>    caller_frame = inspect.currentframe().f_back
>    f = caller_frame.f_locals.get(fname, caller_frame.f_globals.get(fname))
>    return f(x)
>
>    
thanks for this probably safer way to do this (I guess safer, as I know 
nothing about inspect module, but can imagine the value of being 
explicit as to frames and namespaces)
> IMPORTANT USAGE NOTE: never do this :-)
>    
What would you recommand? I do encounter situations where I need 
instantiation based on the name of the thing to instantiate, typically 
passed as an argument by the client code/user.....
thanks in advance,
Johann
> -- Nathaniel
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