Convert string to function name in python

Question

I have many functions with the same prefix. I want to use a combination of strings to invoke the function.

def func_plus_one(v):
    return v+1

def func_plus_two(v):
    return v+2

a='plus_one'
b='plus_two'

So how can I use 'func_'+a and 'func_'+b to use the function?

because 'plus_one', 'plus_two' are also used for other purposes — lanselibai, Aug 28 '20 at 12:07
@superb rain ... dynamic lookup of things to call is a perfectly acceptable thing to be doing — donkopotamus, Aug 28 '20 at 12:08
`for i,n in enumerate(['one', 'two', 'three', 'four']): exec(f'def func_plus_{n}(v): return {v}+i')` — Red, Aug 28 '20 at 12:08
@donkopotamus You don't think there's probably a better way to do what they're actually trying to do? — superb rain, Aug 28 '20 at 12:09
@superb rain ... we don’t know, as we don’t know if `a` is a dynamic variable ... but dynamic resolution of callables based on variables is a pretty common problem. — donkopotamus, Aug 28 '20 at 12:15

score 3 · Accepted Answer · answered Aug 28 '20 at 12:04

If the functions are in the same module as the code needing to reference them, use the globals() of the module. You could call the function indicated by a using:

globals()['func_' + a](x)

If they are in another module, use getattr

getattr(some_module, func_' + a)(x)

Convert string to function name in python

1 Answers1