Create Functions with Optional Arguments in Python

Default arguments in Python

Now, Functions can have required as well as optional arguments. A required argument must be passed for the function to work, while an default argument or parameter is not required for the function to work.

USE A DEFAULT VALUE TO MAKE AN ARGUMENT OPTIONAL

Set an argument to a default data value to make it default. If the user data inputs a value for the argument(parameters), it will override the default main value.

Example 1:
 

def f(required_arg, default_arg1 = "1"):
//Create function with default argument `default_arg1`

print(required_arg, default_arg1)

f("a")

//Calling `f` using default value for `default_arg1`

//RESULTS
a 1
f("a", "b")
//Call `f` using `"b"` for `default_arg1`

//RESULTS
a b

Warning:

Default values need to always be immutable. Using mutable default some data values can cause unexpected behavior.

USE THE *args PARAMETER TO MAKE OPTIONAL ARGUMENTS

Added the *args parameter at the end of a function simple declaration to allow the user to pass in an arbitrary number of arguments as a tuple.

Example 2:
 

def f(a, b, *args):
//Make a function with `*args`

arguments = (a, b) + args
print(arguments)

f(1, 2)
//Calling `f` without default arguments

//RESULTS
(1, 2)
f(1, 2, 3, 4)
//Call `f` with default arguments `3` and `4`

//RESULTS
(1, 2, 3, 4)

I hope you get an idea about keyword argument in python.

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