[Python] Optional variables in funtion

[Wictorian]

How can I add an optional variable to a function in python?

[Sauron]

https://stackoverflow.com/a/9539945

[Wictorian]

24 minutes ago, Sauron said:

https://stackoverflow.com/a/9539945

Do I have to specify the optional variables as 

variable = None

?

[RockSolid1106]

1 minute ago, Wictorian said:

Do I have to specify the optional variables as 

variable = None

?

def function(<variable name> = None):
    your code

 

No, you don't have to specify the variable after that.

Edited October 27, 2021 by RockSolid1106

[Sauron]

5 minutes ago, Wictorian said:

Do I have to specify the optional variables as 

variable = None

?

no, they are optional

[Wictorian]

38 minutes ago, Sauron said:

no, they are optional

What I meant is, do I have to specify it like this?

function(compulsoryVariable, optionalVariable = None):

Or is this okay ?

function(compulsoryVariable,optionalVariable):

 

[Sauron]

11 minutes ago, Wictorian said:

What I meant is, do I have to specify it like this?

Yes, otherwise they won't be initialized to a value when you run the function...

[Wictorian]

19 hours ago, Sauron said:

Yes, otherwise they won't be initialized to a value when you run the function...

Can I specify it with anything other than None?

[Sauron]

1 hour ago, Wictorian said:

Can I specify it with anything other than None?

yes. why don't you check the documentation? https://docs.python.org/3/reference/compound_stmts.html#function-definitions

[codesidian]

Just some quick tips others might find helpful:

You must specify an initial value to your optional args, otherwise they're not optional since they need a value. 

They must be at the end of your functions' args as in:

 def foo (reqArg, reqArg1, reqArg2, optArg = 0, optArg1 = '', optArg2 = True):

And another way would be to pass an args list like:

def bar(reqArg, reqArg1, *args):

or have passed args as a dictionary with kwargs.

def foobar(reqArg, **kwargs):
	# get is used since it allows us to define a default value (if the kwarg wasn't passed)
	print(f"{reqArg} {kwargs.get('message', '')}")

foobar("hello", message="world")
foobar("goodbye")

Output:

hello world
goodbye