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In this program, the calling program must pass a parameter for the required argument and can pass an arbitrary number of parameters following the requiredargument.

The second thing you should pay attention to is the syntax used to call the function named listModifier about six lines up from the bottom of Listing 5 . The function call passes four parameters: aList , bList, cList , and dList , each of which is a reference to a list object.

The reference variable named aList is passed as the first parameter to satisfy the required argument named listA . Note that it is passed using the same syntax as in Listing 1 , Listing 2 , Listing 3 and Listing 4 . Because it is a required argument, it must be passed in the correct order in apositional sense.

The remaining three parameters are passed as variable-length arguments. The interpreter wraps them in a tuple and presents the tuple to the code in the bodyof the function. (You learned about tuples in the earlier module titled Itse1359-1100-Indexing and Slicing Tuples and several modules following that one.)

The code in the body of the function uses the parameter passed as the required argument to append a numeric value to the list referred to by thatparameter.

Although a tuple is immutable, the list objects referred to by the elements in the tuple are mutable. A for loop in the functions iterates from the beginning to the end of the tuple, extracting the references to thelists and appending an increasing numeric value to the end of each list. This is shown in the last four lines of text in Figure 6 .

Note that if the order in which the function processes the arguments is important, the order in which the calling program passes the parameters mustmatch that order because that is the order in which they will be wrapped in the tuple.

Hopefully this explanation along with the code in Listing 5 and the output in Figure 6 will tell you what you need to know about using variable-length function arguments. I do want to caution again, however, that this module does notprovide a complete treatment of function arguments. For a more compete treatment, I will refer you to The Python Tutorial -- More on Defining Functions and tutorialspoint -- Python Functions .

Visualization of variable-length arguments

Figure 7 shows a visualization of the code in Listing 5 part of the way through the execution of the program. Note that in order to reduce the amount of vertical space required to publish the visualization , one of the visualization parameters was changed to "inline primitives and nested objects [default]."

Figure 7. Visualization of variable-length arguments.

Visualization of variable-length arguments.

I recommend that you create a visualization for the code in Listing 5 and step through the program one instruction at a time. As you do that, pay attention to the movements of the red and green arrows on the left, thediagram on the right, and the printed material at the bottom. That should help you to better understand the concept of variable-length arguments.

Run the programs

I encourage you to copy the code from Listing 1 , Listing 2 , Listing 3 , Listing 4 , and Listing 5 . Execute the code and confirm that you get the same results as those shown in in this module. Experiment with the code,making changes, and observing the results of your changes. Make certain that you can explain why your changes behave as they do.

I also recommend that you create visualizations for the code in Listing 1 through Listing 5 . Step through the programs one instruction at a time. As you do that, pay attention tothe movements of the red and green arrows on the left, the diagram on the right, and the printed material at the bottom. That should help you to betterunderstand the concepts embodied in those sample programs.


This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Itse1359-1280-Function Arguments
  • File: Itse1359-1280.htm
  • Published: 10/26/14
  • Revised: 01/31/16

Financial : Although the Connexions site makes it possible for you to download a PDF file for thismodule at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, you should beaware that some of the HTML elements in this module may not translate well into PDF.

I also want you to know that, I receive no financial compensation from the Connexions website even if you purchase the PDF version of the module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale on Amazon.com showing me as the author. Ineither receive compensation for those sales nor do I know who does receive compensation. If you purchase such a book, please beaware that it is a copy of a module that is freely available on cnx.org and that it was made and published withoutmy prior knowledge.

Affiliation : I am a professor of Computer Information Technology at Austin Community College in Austin, TX.


Questions & Answers

do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
how did you get the value of 2000N.What calculations are needed to arrive at it
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