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This module contains review questions and answers keyed to the module titled Itse1359-1440-Class Variables.

Table of contents

Preface

This module is one in a collection of modules on Python designed for teaching ITSE 1359 Introduction to Scripting Languages: Python at Austin Community College in Austin, TX.

This module contains review questions and answers keyed to the module titled Itse1359-1440-Class Variables .

Once you study that module, you should be able to answer the review questions in this module.

The questions and the answers in this module are connected by hyperlinks to make it easy for you to navigate from the question to the answer and back again.

(Note to blind and visually impaired students: with the exception of two bitmap images that are used solely as spacers to separate the questionsection from the answer section, all of the material in this module is presented in plain text format and should be accessible using an audio screen reader or abraille display. Note however that the required indentation may not be properly represented by an audio screen reader.)

Questions

Question 1

True or False? The code in Figure 1 produces the output shown in Figure 2 except that the hexadecimal values may change from one run to the next.

Figure 1 . Question 1 program code.
class TestClass(object): classVar = [1,2,3,4]def modifyClassVar01(self,var): self.classVar.append(var)def printClassVar01(self): print(str(self)[10:40]+ ": " + str(self.classVar)) ref01 = TestClass()ref02 = TestClass() ref01.modifyClassVar01("a")ref02.modifyClassVar01("b") ref01.printClassVar01()ref02.printClassVar01()
Figure 2 . Question 1 possible output.
TestClass object at 0x00504910: [1, 2, 3, 4, 'a'] TestClass object at 0x00542710: [1, 2, 3, 4, 'b']

Go to answer 1

Question 2

True or False? The code in Figure 4 produces the output shown in Figure 5 except that the hexadecimal values may change from one run to the next.

Figure 4 . Question 2 program code.
class TestClass(object): classVar = 1234def shadowClassVariable(self): self.classVar = "ABCD"def printClassVar(self): print(str(self)[10:40]+ ": " + str(self.classVar)) ref01 = TestClass()ref02 = TestClass() ref01.printClassVar()ref02.printClassVar() ref01.shadowClassVariable()ref01.printClassVar() ref02.printClassVar()TestClass.classVar = True ref01.printClassVar()ref02.printClassVar()
Figure 5 . Question 2 possible output.
TestClass object at 0x02282710: 1234 TestClass object at 0x022825F0: 1234TestClass object at 0x02282710: ABCD TestClass object at 0x022825F0: 1234TestClass object at 0x02282710: ABCD TestClass object at 0x022825F0: True

Go to answer 2

Figure index

What is the meaning of the following two images?

These images were inserted here simply to insert some space between the questions and the answers to keep them from being visible on the screen at thesame time.

Spacer image of a rabbit and a penguin.

This image was also inserted for the purpose of inserting space between the questions and the answers.

Spacer image of a penguin and some houses.

Answers

Answer 2

True.

Go back to Question 2

Answer 1

False. The actual output is shown in Figure 3 . Modifying a class variable at runtime impacts all of the objects that have been instantiated from that classbecause class variables are shared among all objects instantiated from the class.

Figure 3 . Question 1 actual output.
TestClass object at 0x00504910: [1, 2, 3, 4, 'a', 'b'] TestClass object at 0x00542710: [1, 2, 3, 4, 'a', 'b']

Go back to Question 1

Miscellaneous

This section contains a variety of miscellaneous information.

Housekeeping material
  • Module name: Itse1359-1440r-Review
  • File: Itse1359-1440r.htm
  • Published: 10/27/14
  • Revised: 03/04/15
Disclaimers:

Financial : Although the Connexions site makes it possible for you to download aPDF file for this module at no charge, and also makes it possible for you to purchase a pre-printed version of the PDF file, youshould be aware 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 ofthe module.

In the past, unknown individuals have copied my modules from cnx.org, converted them to Kindle books, and placed them for sale onAmazon.com showing me as the author. I neither receive compensation for those sales nor do I know who does receive compensation. If youpurchase such a book, please be aware that it is a copy of a module that is freely available on cnx.org and that it was made andpublished without my prior knowledge.

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

-end-

Questions & Answers

A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
Aislinn Reply
cm
tijani
what is titration
John Reply
what is physics
Siyaka Reply
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Jude Reply
Can you compute that for me. Ty
Jude
what is the dimension formula of energy?
David Reply
what is viscosity?
David
what is inorganic
emma Reply
what is chemistry
Youesf Reply
what is inorganic
emma
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
Krampah Reply
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
Sahid Reply
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
Samuel Reply
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Joseph Reply
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
Ryan
what's motion
Maurice Reply
what are the types of wave
Maurice
answer
Magreth
progressive wave
Magreth
hello friend how are you
Muhammad Reply
fine, how about you?
Mohammed
hi
Mujahid
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
yasuo Reply
Who can show me the full solution in this problem?
Reofrir Reply
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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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