dynamically mapping function name using getattr in python

Question

import json

class Myclass():

    def __init__(self):

        with open("file_name.json", "r") as read_file:
            data = json.load(read_file)

        for key in data:
            print key
            key = getattr(self,'func_name')

    def func_name(self,arg):
        print "Pass"

obj = Myclass()
obj.func_name("test")
obj.key_from_file("test")

Output:

key_from_file
Pass
Traceback (most recent call last):
  File "get_at.py", line 22, in <module>
    obj.key_from_file("test")
AttributeError: Myclass instance has no attribute 'key_from_file'

I want to dynamically map all key in json file to func_name, so whenever we call obj.key_from_file("test") which should call obj.func_name("test")

How to do that ?

I don't get the question. At all. Why would you expect `obj` to have a `key_from_file` method even though you never defined one? And what's the point of the `func_name` method? — Aran-Fey, Jun 12 '18 at 11:52
Duplicate: https://stackoverflow.com/questions/285061/how-do-you-programmatically-set-an-attribute — Aran-Fey, Jun 12 '18 at 12:05
Possible duplicate of [How do you programmatically set an attribute?](https://stackoverflow.com/questions/285061/how-do-you-programmatically-set-an-attribute) — Netwave, Jun 12 '18 at 12:19

Netwave · Accepted Answer · 2018-06-12T11:56:57.060

0

Use setAttr for setting the attribute in the object:

import json

class Myclass():

    def __init__(self):
        with open("file_name.json", "r") as read_file:
            data = json.load(read_file)
        for key in data:
            print key
            setattr(self, key, self.func_name) #we create an attr with the key as name and the funct_name function as value.

    def func_name(self,arg):
        print "Pass"

obj = Myclass()
obj.func_name("test")
obj.key_from_file("test")

Here you have a live example

edited Jun 12 '18 at 11:56

answered Jun 12 '18 at 11:48

Netwave

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How does this answer the question? The code will still throw the same exception. – Aran-Fey Jun 12 '18 at 11:53
@Aran-Fey, no it will not, if the key is on the json file – Netwave Jun 12 '18 at 11:54
So the question is literally just "How do I dynamically set an attribute"? We have dupes for that. – Aran-Fey Jun 12 '18 at 12:04

dynamically mapping function name using getattr in python

1 Answers1