How can I define a program of Python with optional arguments?

 For implementing an optional argument like discount percentage in the context of a Python function, you can set a default value for the argument. Here is an example of it:-

Def calculate_ total_ cost( cart_ items, discount_ percentage=0): 
Total_ cost = sum( cart_ items)
Discounted_ cost = total_cost – ( total_ cost* discount_ percentage/ 100)
Return discounted_ cost
Users can also call this above specific function without providing the ‘discount_ percentage’ argument
# Without Discount
Total_ without_ discount= calculate_ total_ cost[ 20, 30, 40])
Print( total_ without_ discount)
#With Discount
Total_ with_ discount= calculate_ total_ cost([ 20, 30, 40], discount_ percentage= 10)
Print( total_ with_ discount)

In the first above example, the default value of the discount percentage is 0, on the other hand, the default value of the discount percentage is 10%. Join the Python certification course for more information.