Csc148H1: Introduction To Computer Science

Front 1

How would you write this Python function?

Back 1

Front 2

In Python, is this statement TRUE or FALSE?

5 is "five"

Back 2

FALSE

Front 3

What boolean would be returned if I put "w1 == w2"?

Back 3

True

Front 4

What boolean would be returned if I put "w1 is w2"?

Back 4

False

Front 5

How do most modern computers store and manipulate data as?

Back 5

As binary digits represented by bits (strings of 0s and 1s... or high and low voltage or dipoles or etc...)

Front 6

How do you define a class API?

Back 6

Choose a class name and write a brief description in the class docstring

Write some examples of client code that uses your class

Decide what services your class should provide as public methods

Decode which attributes your class hsould provide without calling a method, list them in class dostring

Front 7

How would you implement a class?

Back 7

First, usually contain special methods such as __init__, __eq__ and __str__

Second, include body of other methods

Finally, do some testing

Front 8

In class methods like __str__(self), what are some alternatives to using self?

Back 8

Python allows point, me, yo or ego as alternatives to self

Front 9

What is the first parameter of class methods?

Back 9

The first parameter in a method definition is a reference to the class isntance and method belongs to

Front 10

What does the special method __repr__ do?

Back 10

Returns a canonical string representation of the object

Unambiguous

Front 11

What happens if you do not implement a special method __str__ in a class?

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Python will automatically use __repr__ in its place

Front 12

How do you write single line comments in Python?

Back 12

Using the "#"

Front 13

For the following class, write an __init__ for it:

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Front 14

Write an __eq__ for the following class:

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Front 15

Write an __str__ for the following class:

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Front 16

Finish the distance_to_origin method:

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Front 17

Finish the distance method:

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Front 18

Finish the move method:

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Front 19

Write an __ad__ to the following class:

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Front 20

What would happen if other.x does not have an "x" attribute?

Back 20

It will produce an error

Front 21

Are attributes in Python, by default, public or private?

Back 21

Public

Front 22

What does it mean when a Python attribute is public?

Back 22

Meaning it is completely possible for anyone to have access to it

Front 23

What is Python's property function?

Back 23

property()

Re-directs access to an attribute so that is must use a method

Takes four arguments

Front 24

What attributes does the Python function property() take?

Back 24

Method to get value

Method to set value

Method to delete attribute/value

Some documentation

Front 25

In Python, what is composition?

Back 25

Uses user-defined types in Python code anywhere you would use built-in types that include using user-defined types inside new user-defined types

In other words, if we need feature of type A in user-defined type B, simply include an instance of A in our class B

Front 26

Why would you want to use composition in Python?

Back 26

Build increasing complex types using already-built types thus reducing amount of complexity have to deal with at any given time

Front 27

In Python, what is inheritance?

Back 27

Allows user to inherit methods and attributes and modify or extend some or even completely override them

Front 28

In Python, what is the difference between inheritance and composition?

Back 28

Composition: include an instance of exsting class in new class and use its features

Inheritance: New class that inherit all methods and attributes of parent class

Front 29

Write an __init__ for the folowing class:

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Front 30

Write a __str__ for the following class:

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Front 31

Write an __eq__ for the following class:

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Front 32

For the following class, why would the following code not be a correct choice for the __eq__ method?

return self.num * other.denom == other.n

Back 32

Though it would work sometimes, it might not always work the way we want because of rounding error from limtations of representing numbers on the computer

Front 33

Finish the to_float function

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Front 34

Write an __add__ for the following class:

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Front 35

What is the special class __mul__?

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Return a * b, for a and b numbers (multiplication)

Front 36

Write an __mul__ for the following class:

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Front 37

In Python, what is the special class __lt__?

Back 37

Less than

Front 38

Write a __lt__ for the following class:

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Front 39

How would you denote something as private in Python?

Back 39

Using a leading underscore like _this in the method's name

Front 40

What does the leading underscore indicate in a Python method?

Back 40

"Private" (not actually private but by convention)

Front 41

Create a private method for the following class that changes the denominator

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Front 42

What is raise Exceptions in Python?

Back 42

Brings fourth a message when an error occurs

Front 43

How do you import a class from another Python file?

Back 43

from [directory].[file_name] import [class]

Front 44

Create an __init__ for the following class:

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Front 45

Finish this private method for this class

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Front 46

Lets say a _set_perimeter was already created (making a self._perimeter), create a _get_perimeter for the following class

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Front 47

Finish the _set_area method to create self._area

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Front 48

Lets say a _set_area was already created (making a self._area), create a _get_area for the following class

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Front 49

When creating a class, how do you inherit methods and attributes from another class?

Back 49

Put the name of the Class you wish to inherit in the class name

For example, [class New_Class(to_inherit_class)]

Front 50

What does the Python function input([prompt] do?

Back 50

Read a string from standard input

The trailing newline is stripped

The prompt string,if given, is printed without a trailing newline before reading

Front 51

What does the Python function len(x) do?

Back 51

Returns an int

Return the length of the list, tuple, dict, or string x

Front 52

What does the Python function open(name[, mode]) do?

Back 52

Returns file open for reading, writing, or appending

Opens a file

Legal modes are r (read), w (write), and a (append)

Front 53

What does the Python function range([start], stop, [step]) do?

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Returns list-like-object of int

Return the integers starting with start and ending with stop - 1 with step specifyingthe amount to increment (or decrement)

If start is not specified, the list starts at 0

If step is not specified,the values are incremented by 1

Front 54

The following code is for creating a new list with the squares of all elements of L = list(range(100))

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Front 55

What is the general pattern for comprehensions?

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[expression for name in iterable if condition]

Front 56

What is an Abstract data types (ADTs)?

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An ADT specifies the intended meaning of data it stores and operations it provides on that data

It is NOT about how to store and manipulate data in programming

Front 57

What is an ADT interface?

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Tells the clients what operations the ADT is capable of

Front 58

Why would changing an ADT after publishing it can be dangerous?

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1) You have to inform clients of change

2) It can cause clients to have to re-write their code

Front 59

What are the common types of ADTs?

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Sequence of items (can be added, removed, accessed, etc...)

Collection of items accessed by their associated keys

Specalized list where we only have access to most recently added item

Front 60

What is a stack class?

Back 60

Stack is another example of an ADT

It stores items, provides operaiton to remove/pop top item, provides operation to add/push a new item ontop of the stack and provides a way to tell whether a stack is empty

Front 61

Give a verbal description of what a stack class does?

Back 61

So if you has function A calls function B, so function B must be removed first before function A can be removed from that stack

With this, you cannot access the rest

Front 62

Why would you use unit testing (unittest) in your ADT?

Back 62

To make sure that your particular implementation remains consistent with your ADT's interface

Front 63

How would you use unit testing (unittest) in your ADT's interface?

Back 63

Import module unittest

Subclass unittest.Testcase for your tests and begin each method that carries out a test with the string test

Compose tests before and during implementation

Front 64

What is test driven philosophy?

Back 64

You write tests before you write the code so before you write a segment of a code, you can run tests during

Front 65

Let's say you are creating a new class (Square) but you are inherting from another (Shape). In your __init__, you want to keep the old corners property but create a new color and name, how would you do that?

Back 65

Front 66

Stack classes need some way to determine if they are empty, write a code to determine if a stack is empty or not

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Front 67

Create shorter/comprehensive code for the following:

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Front 68

Create shorter/comprehensive code for the following:

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Front 69

What is the setUp function/method?

Back 69

Creates (or set-ups) an empty version of a class being tested

Front 70

What is a tearDown function/method?

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Creates a fresh stack

So each start of the test can begin with a clean, empty version that is independent of another test

Front 71

Why would you want a tearDown function/method be set to None during a test?

Back 71

Starts a new test with a clean, empty variable that is independent of another test

When set to None, it can prevent multiple instances of the same variable when testing (like stack)

Front 72

When doing unit testing (unittest), how does the self.assertEqual or assert work?

Back 72

If an error occurs, the assert message will be displayed as an AssertionError message

Front 73

What does raise NotImplementedError do?

Back 73

If the subclass of the class this raise belongs to does not have the method that this raise belongs to, an error will occur asking for that method to exist

Front 74

Finish the following function:

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Front 75

What does Python's isinstance() do?

Back 75

Return whether an object is an instance of a class or of a subclass thereof

Parameters: obj, class or tuple, /

Front 76

What is depth in Python?

Back 76

How many list or sublists a input has

Example: ([1, 2, 3]) has depth of 1 while ([1, [2, [3, 3, 3,], 2]]) has a depth of 3

Front 77

What is a flat list or flat depth?

Back 77

No sublists (depth of 1)

Front 78

What is a base case for recursion?

Back 78

Ifinstance of data structure cannot be broken down into smaller substructures ofthe same sort and solution derived by solving those smaller problems, processthe data structure directly without recursion

Front 79

What is generative recursion?

Back 79

Recursive code that generates amller isntances of input data structure that correspond to smaller subproblems

Front 80

Why is this generative recursion?

Back 80

Even if you constructed integers as a recursive data structure, it is very unlikely that the structure of m or n would always have substructure m&n

This is another case where the developer thought hard about the problem and generated the data for the recursive step: n and m%n

Front 81

Complete the following function:

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Front 82

Complete the following function:

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Front 83

Complete the following function:

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Front 84

What helper methods does this function call?

Back 84

sum (already sums ints in a list) and isinstance

Front 85

What is the point of tracing through a function?

Back 85

To convience yourself that it works and you know what it is doing

Front 86

Trace sum_list(27)

Back 86

isinstance is False, go straight to else block and return 27

Front 87

Trace sum_list([4, 1, 8])

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Front 88

Trace sum_list([4])

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Front 89

Trace sum_list([])

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Front 90

Trace sum_list([4, [1, 2, 3], 8])

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Front 91

Trace sum_list([[1, 2, 3], [4, 5], 8])

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23

Front 92

Trace sum_list([1, [2, 2], [2, [3, 3, 3], 2]])

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Front 93

Trace sum_list([1, [2, 2], [2, [3, [4, 4], 3, 3], 2]])

Back 93