Ignore passed arguments

Question

Is it possible to ignore passed/overgiven arguments in a method?

Here is an example from something I want to do:

def event_handler(one, two):
   print(one)
   print(two)

And at another place:

event_handler(one, two, three)

I mean that the third argument is optional. I've tried in Python Fiddle, but it doesn't work without an error.

Bhargav Rao · Accepted Answer · 2015-03-28T15:13:12.777

3

Make the third an default argument

def event_handler(one, two, third = None):

Then do error handling, but as it is default, it is easy.

def event_handler(one, two, third = None):
   print(one)
   print(two)
   if (three):
        print(three)

edited Mar 28 '15 at 15:13

answered Mar 28 '15 at 15:12

Bhargav Rao

Yes, but is it possible to take that without setting a default for an argument? – Jonniboy Mar 28 '15 at 15:12
1

AFAIK. You need to add a default value. – Bhargav Rao Mar 28 '15 at 15:13
Ok, thank you for answering such a nooby question. ^^ – Jonniboy Mar 28 '15 at 15:15
Look up `*args` and `**kwargs`. They maybe of help to you – Bhargav Rao Mar 28 '15 at 15:16
1

whats wrong with explicitly setting a default value? *args and **kwargs are better if you are overridding an existing method that you dont know the exact signature for – Joran Beasley Mar 28 '15 at 15:26
@Jonniboy You may wanna have a look at Joran's perfect explanation as to when to use def-args and when to use var-args. – Bhargav Rao Mar 28 '15 at 15:31
And also take a look at [this](http://stackoverflow.com/questions/27732506/what-is-a-better-way-to-define-a-class-init-method-with-optional-keyword-ar/27732540#27732540) answer – Bhargav Rao Mar 28 '15 at 15:45

Nizam Mohamed · Answer 2 · 2015-03-28T15:31:02.600

2

Use variable arguments with *args.

def f(*args): pass

Access the vars as a list like args[0],... Or,

def f(required_arg1, required_arg2, *optional_args): pass

edited Mar 28 '15 at 15:31

answered Mar 28 '15 at 15:14

Nizam Mohamed

the problem with this is it obscures the argument definition ... It is much better to use a default argument for this case imho ... – Joran Beasley Mar 28 '15 at 15:26

2 Answers2