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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.

Miscellaneous

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
Disclaimers:

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.

-end-

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
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What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
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biomolecules are e building blocks of every organics and inorganic materials.
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research.net
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Introduction about quantum dots in nanotechnology
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nano basically means 10^(-9). nanometer is a unit to measure length.
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Do somebody tell me a best nano engineering book for beginners?
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there is no specific books for beginners but there is book called principle of nanotechnology
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what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
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.
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what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
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Mostly, they use nano carbon for electronics and for materials to be strengthened.
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CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
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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.
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s.
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for screen printed electrodes ?
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of graphene you mean?
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in general
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Graphene has a hexagonal structure
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Source:  OpenStax, Itse 1359 introduction to scripting languages: python. OpenStax CNX. Jan 22, 2016 Download for free at https://legacy.cnx.org/content/col11713/1.32
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