accessing *args from within a function in Python

Question

Hi everyone this is probably something extremely simple that i'm overlooking but can someone point me in the right direction for how to handle this problem.

def nodeFunction(self,*args):
    return self[1] + self[2]

Basically what I am trying to do is grab the data passed in through the arguments. I am just stuck on the syntax for referencing the arguments inside the function when using *args.

A neat rule of thumb in Python is that names have to come from somewhere; they don't get magically inserted by the language. (An instance method refers to the instance as `self` only because that is the first argument to the method -- there's no magic `this`. A setter for a property refers to the value it is setting as an argument -- there's no magic `value`. If you want to use a function inside a module `foo`, you have to import `foo` so that the interpreter knows what it is. Etc.) — Katriel, Jul 30 '11 at 13:58

score 24 · Accepted Answer · edited Jun 25 '19 at 18:00

24

args is simply a tuple:

def nodeMethod(self, *args):
    return args[0], args[1]

Is that what you mean?

Note that there's nothing special about "args". You could use any variable name. It's the * operator that counts.

>>> class Node(object):
...     def nodeMethod(self, *cornucopia):
...         return cornucopia[0], cornucopia[1]
... 
>>> n = Node()
>>> n.nodeMethod(1, 2, 3)
(1, 2)

Still, "args" is the most idiomatic variable name; I wouldn't use anything else without a good reason that would be obvious to others.

edited Jun 25 '19 at 18:00

Karl Sebby

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answered Jul 30 '11 at 12:17

senderle

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Bloody hell, I am such an idiot, sorry im still getting the hang of python. Thats exactly what I was looking for thank you. Ill accept the answer when I can. – SacredGeometry Jul 30 '11 at 12:21

score 5 · Answer 2 · edited Aug 04 '12 at 01:51

5

def nodeFunction(self, arg1, arg2, *args)

*arg in argument list means: pass the remaning arguments as a list in variable arg. So check how to handle lists. Note: list index starts from 0.

edited Aug 04 '12 at 01:51

Bill the Lizard

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answered Jul 30 '11 at 12:19

Karoly Horvath

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accessing *args from within a function in Python

2 Answers2