Call method from string inside class?

Question

I am trying to call fucntions using string value. Here is a simple example of my problem. How to call method(line) properly? I tried different solutions and got success only with @staticmethod but this is not what I want.

class A():

    def prime(self, key):
        line = 'Good'
        method = getattr(A, key)
        method(line)

    def add1(self, string):
        print string + ' day!'

    def add2(self, string):
        print string + ' evening!'



def main():
    test = A()
    test.prime('add1')
    test.prime('add2')

if __name__ == "__main__":
    main()

why do you want it to be a string when you can just call it normally — L_Church, Mar 02 '18 at 14:01
Is there a reason you need to pass a string rather than a reference to the method itself? test.prime(A.add1), then def prime(self, method): method(self, "Good")` — chepner, Mar 02 '18 at 14:49
Yes, because user has an access to parameters and it is easier to make inputs as simple strings. I hope, now it's more clear — Gatto Nou, Mar 02 '18 at 16:29

Phydeaux · Answer 1 · 2018-03-02T14:09:51.833

2

You need to pass self to getattr instead of the class name:

method = getattr(self, key)
method(line)

Also, if this is Python 2, you should inherit from object in most cases, to use new-style classes:

class A(object):

edited Mar 02 '18 at 14:09

answered Mar 02 '18 at 14:04

Phydeaux

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@Gatto you're welcome :-). If this answer solves your problem, consider accepting it. – Phydeaux Mar 02 '18 at 14:42

score 1 · Answer 2 · answered Mar 02 '18 at 14:46

1

Use operator.methodcaller:

def prime(self, key):
    operator.methodcaller(key, "Good")(self)

answered Mar 02 '18 at 14:46

chepner

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Call method from string inside class?

2 Answers2