Question 1

In the remove method for LinkedBag, if probe points to the node at the head of the linked structure, trailer will point to the tail.

Accepted Answer

A) True 
 B)False

Question 2

The code for the __iter__ method is shown below. What is the missing code?
Def __iter__(self) :

While cursor < len(self) :
Yield self.items[cursor]
Cursor += 1

Accepted Answer

A)   cursor = 0
B)   cursor = 1
C)   cursor = self.size
D)   cursor = len(self) E) A) and B)
F) A) and C)

Question 3

Which of the following is one of the hallmarks of well-designed software?

Accepted Answer

A)   a random grouping of interfaces to ensure secure code
B)   an interface that is tightly coupled to the implementation
C)   the clean separation of interfaces from implementations
D)   a sophisticated interface with a high learning curveE) B) and D)
F) None of the above C

Question 4

What does Python do when it sees a for loop on an iterable object?

Accepted Answer

A)   executes a do loop
B)   runs the __iter__ method
C)   runs the clear method
D)   executes a return statementE) B) and C)
F) A) and D)

Question 5

Data that is needed to represent the state of a collection are assigned instance variables in the __help__ method of the class.

Accepted Answer

A) True 
 B)False

Question 6

Class diagrams show the relationships among classes at various levels of detail.

Accepted Answer

A) True 
 B)False

Question 7

A precondition is a statement of what must be true for a method to perform its actions correctly.

Accepted Answer

A) True 
 B)False

Question 8

In the ArrayBag class, what must the __init__ method do if a source collection is specified?

Accepted Answer

A)   the new instantiation of the bag must be copied to the source collection.
B)   the source collection must be initialized with the clear method
C)   the data in the source collection must be deleted
D)   the data in the source collection must be copiedE) A) and C)
F) A) and D)

Question 9

Each time you run Python's document function to obtain information about a module, data type, method, or function, you are accessing documentation about that resource's interface.

Accepted Answer

A) True 
 B)False

Question 10

The following code copies the data from a specified source collection in the LinkedBag __init__ method. What is the missing code? for item in sourceCollection:

Accepted Answer

A)   add(item.self) 
B)   self.add(item) 
C)   self.item(add) 
D)   self.item = source.itemE) A) and C)
F) A) and B)

Question 11

What testing tool can be used to help ensure that a resource meets its requirements?

Accepted Answer

A)   unittest
B)   pytest
C)   pyunit
D)   unitcheckE) C) and D)
F) All of the above

Question 12

Which of the following methods will require changes between the ArrayBag and the LinkedBag class?

Accepted Answer

A)   isEmpty
B)   remove
C)   __eq__
D)   __len__E) B) and C)
F) None of the above

Question 13

While desirable, testing is not a critical part of software resource development.

Accepted Answer

A) True 
 B)False  False

Question 14

What is one of the pieces of data that must be initialized in the __init__ method in the LinkedBag class?

Accepted Answer

A)   an array
B)   a linked structure
C)   a physical size
D)   a string pointerE) A) and C)
F) None of the above

Question 15

What method does Python run when it sees the in operator used with a collection?

Accepted Answer

A)   __contains__
B)   __iter__
C)   __eq__
D)   __add__E) All of the above
F) None of the above A

Question 16

How can the performance of the in and remove functions be described in the two bag implementations?

Accepted Answer

A)   they take linear time
B)   they take constant time
C)   the performance is exponential according to the size of the bag
D)   the performance is logarithmic according to the size of the bagE) B) and C)
F) All of the above

Question 17

Which is true about a bag collection?

Accepted Answer

A)   it is an unordered collection
B)   it is a standard collection type in Python
C)   bags can contain only numeric objects
D)   bags are of a fixed sizeE) A) and D)
F) All of the above

Question 18

A docstring is a string enclosed in double quotes that will be displayed when Python's help function is run on a resource.

Accepted Answer

A) True 
 B)False

Question 19

You can use a for loop on any collection.

Accepted Answer

A) True 
 B)False

Question 20

Which of the following is NOT a goal of the barrier that separates an interface from implementation?

Accepted Answer

A)   allows users to quickly glue resources together
B)   allows alternative implementations of the same resource
C)   changes to a resource's implementations do not disturb user code
D)   increases the learning curve for resource's usersE) All of the above
F) B) and C)

Exam 5: Interfaces, Implementations, and Polymorphism

In the remove method for LinkedBag, if probe points to the node at the head of the linked structure, trailer will point to the tail.

Correct AnswerverifiedShow Answer

The code for the __iter__ method is shown below. What is the missing code? Def __iter__(self) : < missing code > While cursor < len(self) : Yield self.items[cursor] Cursor += 1

Correct AnswerverifiedShow Answer

Which of the following is one of the hallmarks of well-designed software?

Correct AnswerverifiedC

What does Python do when it sees a for loop on an iterable object?

Correct AnswerverifiedShow Answer

Data that is needed to represent the state of a collection are assigned instance variables in the __help__ method of the class.

Correct AnswerverifiedShow Answer

Class diagrams show the relationships among classes at various levels of detail.

Correct AnswerverifiedShow Answer

A precondition is a statement of what must be true for a method to perform its actions correctly.

Correct AnswerverifiedShow Answer

In the ArrayBag class, what must the __init__ method do if a source collection is specified?

Correct AnswerverifiedShow Answer

Each time you run Python's document function to obtain information about a module, data type, method, or function, you are accessing documentation about that resource's interface.

Correct AnswerverifiedShow Answer

The following code copies the data from a specified source collection in the LinkedBag __init__ method. What is the missing code? for item in sourceCollection: < missing code >

Correct AnswerverifiedShow Answer

What testing tool can be used to help ensure that a resource meets its requirements?

Correct AnswerverifiedShow Answer

Which of the following methods will require changes between the ArrayBag and the LinkedBag class?

Correct AnswerverifiedShow Answer

While desirable, testing is not a critical part of software resource development.

Correct AnswerverifiedFalse

What is one of the pieces of data that must be initialized in the __init__ method in the LinkedBag class?

Correct AnswerverifiedShow Answer

What method does Python run when it sees the in operator used with a collection?

Correct AnswerverifiedA

How can the performance of the in and remove functions be described in the two bag implementations?

Correct AnswerverifiedShow Answer

Which is true about a bag collection?

Correct AnswerverifiedShow Answer

A docstring is a string enclosed in double quotes that will be displayed when Python's help function is run on a resource.

Correct AnswerverifiedShow Answer

You can use a for loop on any collection.

Correct AnswerverifiedShow Answer

Which of the following is NOT a goal of the barrier that separates an interface from implementation?

Correct AnswerverifiedShow Answer

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The code for the iter method is shown below. What is the missing code? Def iter(self) : < missing code > While cursor < len(self) : Yield self.items[cursor] Cursor += 1

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C

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Data that is needed to represent the state of a collection are assigned instance variables in the help method of the class.

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In the ArrayBag class, what must the init method do if a source collection is specified?

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The following code copies the data from a specified source collection in the LinkedBag init method. What is the missing code? for item in sourceCollection: < missing code >

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False

What is one of the pieces of data that must be initialized in the init method in the LinkedBag class?

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A

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