Session 1 - Part I

Question 1

On any computer everything is stored in a

Answer 1

file system

Question 2

What is a file system? - (2)

Answer 2

A file system is the organizational structure employed by operating systems to manage and store data on storage devices.

It establishes a hierarchical arrangement for organizing files and directories, facilitating efficient data access and retrieval.

Question 3

What analogy is often used to describe the structure of a file system, and what is its ‘trunk’ equivalent?

Answer 3

A file system is often likened to a tree structure, where the ‘trunk’ represents the ‘base’ of file system.

Question 4

The ‘base’ of the file systems is commonly denoted by computer as:

Answer 4

single slash ‘/’ character or known as ‘root directory’

Question 5

What is a root directory? - (2)

Answer 5

The root directory is the highest-level directory in a file system hierarchy, serving as the starting point of directory tree from which all other directories and files branch.

It is denoted by a single forward slash (/)

Question 6

Diagram of file system at YNiC

Answer 6

Question 7

What is the path of the file “Thesis.doc” provided in the diagram?

Answer 7

The path of the file “Thesis.doc” is /home/alex/.

Question 8

Why is it important to avoid certain ‘funny’ characters like spaces, question marks etc… in file system names?

Answer 8

Spaces and exclamation marks have special meaning to coders so when using them to name files in file system it becomes very complicate to manage and navigate to files in file system using code as using special characters on the file

Question 9

Naming file in file system using ‘funny characters’ example

Answer 9

My Cat Pictures!.doc

Question 10

What advice is given regarding file naming conventions in the notes, and why is it important to follow such conventions? - (2)

Answer 10

The notes suggest avoiding ‘funny’ characters like spaces and question marks in file names, advising the use of underscores instead.

This practice is crucial to prevent complications in file management and ensure seamless navigation within the file system.

Question 11

Example of following conventions when naming files in file system

So instead of: My Cat Pictures!.doc

use…

Answer 11

My_Cat_Pictures.doc

Question 12

What special character precedes commands executed within the Colab code cells, and what does it signify? - (2)

Answer 12

Commands executed within Colab code cells are prefixed with the ‘%’ sign, indicating that they are special commands (not Python).

These commands allow users to perform various non-Python operations within the notebook environment

Question 13

What command is used to change the current directory within a Colab code cell?

Answer 13

The ‘%cd’ command is employed to change the current directory within a Colab code cell

Question 14

what argument does %cwd require?

Answer 14

It necessitates specifying the desired directory it wants to change the current directory to as its argument.

Question 15

What does %cwd / mean?

Answer 15

Changes the current directory to the ‘root’ directory of the file system

Question 16

What does the ‘%pwd’ command do within a Colab code cell?

Answer 16

The ‘%pwd’ command in a Colab code cell prints the present working directory, revealing the current location within the file system.

Question 17

What does %pwd stand for?

Answer 17

‘Print Working Directory’ or ‘Where am I?’

Question 18

What does %cd stand for?

Answer 18

Change Directory

Question 19

What command is used to list the contents of the current directory within a Colab code cell?

Answer 19

The ‘%ls’ command

Question 20

What does %ls represent in Colab code cell?

Answer 20

‘List’

Question 21

What does %ls -lt represent in Colab code cell?

Answer 21

%ls -lt’ stands for ‘List - Long, sorted by time’

Question 22

How can one list the contents of the current directory in a ‘long’ format sorted by ‘time’ within a Colab code cell?

Answer 22

To list the items in the current directory in a ‘long’ format sorted by ‘time’ within a Colab code cell, the ‘%ls -lt’ command is used.

Question 23

The directories exist in a

Answer 23

‘tree’

Question 24

What will this code give you?

%cd /
%pwd
%ls
%ls - lt
- (3)

Answer 24

%pwd = given /

%ls - lists all contents of current working directory (from bin@ to cuda-keyring)

%ls-lt (output starting from total 100) - lists all contents of current working directory by working out file size and sorts them by date

Question 25

What does the ‘%history’ command do in Colab notebooks?

Answer 25

The ‘%history’ command in Colab notebooks displays a history of codes and commands written

Question 26

What does the ‘%magic’ command do in Colab notebooks?

Answer 26

The ‘%magic’ command in Colab notebooks provides information and documentation about available commands and their functionalities.

Question 27

List all the special commands used in Colab notebooks - (7)

Answer 27

‘%cd’,
‘%pwd’, ‘
%ls’,
‘%ls -lt’,
‘%history’,
‘%magic’.
&mkdir

Question 28

What does the ‘%mkdir’ command do

Answer 28

It creates a new directory within the current working directory.

Question 29

Quick Exercise
Practice typing commands in the code window below and run them.

Check what your present working directory is and make a note of it (this might be your home directory on the system on which you are working)

Change to another directory to home

Check where your present working directory

Produce a new directory called test

List contents in test

Change current working directory to test

Answer 29

%pwd
Output: /content/sample_data

%cd /home (root then place we want to go)

Output: /home

%pwd - check where we are
Output: ‘/home’

%mkdir test
No output

%ls
Output: test/

%cd test
Output: /home/test

Question 30

What character represents comments in Python?

Answer 30

The hashtag symbol (#) represents comments in Python.

Question 31

Why are comments important in programming?

Answer 31

Comments help programmers add notes, explanations, or documentation to their code/program in English, making it easier for person reading the script understanding what was happening

Question 32

Comments are parts of your code that the

Answer 32

computer ignores

Question 33

What should you consider when writing comments in your code? - (2)

Answer 33

When writing comments, it’s essential to be professional, helpful, and concise (don’t write too much).

Provide explanations for why certain actions are taken in your code, in addition to describing what the code is doing

Question 34

Example of comment

Answer 34

This is a comment

Question 35

Example of writing comment of explaiing why you are doing something as well as describing what the code is doing?

Answer 35

print(‘Hello Again! This is running in Colab!’) # Print out a nice message on the otput.

Question 36

What is the output of this code?

print(‘Hello Again! This is running in Colab!’) # Print out a nice message on the otput.

Answer 36

Hello Again! This is running in Colab!

Question 37

What does the following line of code do?

print(‘Hello Again! This is running in Colab!’) # Print out a nice message on the otput.

Answer 37

The line of code prints the message ‘Hello Again! This is running in Colab!’ to the output console.

Question 38

What is the purpose of the comment in the following line of code?

print(‘Hello Again! This is running in Colab!’) # Print out a nice message on the otput.

Answer 38

The comment provides a note or explanation about the code’s functionality without being executed by the interpreter

Question 39

What does the following code do?

print(“Hello World!”)

Answer 39

The code prints the string “Hello World!” to the output console.

Question 40

What is the purpose of the print() function in Python?

Answer 40

The print() function in Python is used to output text or variables to the output console/terminal

Question 41

How do you use the print() function to display a message? - (2)

Answer 41

To display a message using the print() function, you provide the message inside parentheses as an argument. For example:

print(“Hello, World!”)

Question 42

What does the print() function do when given multiple arguments? - (4)

Answer 42

When provided with multiple arguments, the print() function outputs each argument separated by a space by default.

Example:
print(“Hello”, “World!”)

This would print:

Hello World!

Question 43

How can strings be created in Python? - (3)

Answer 43

Strings in Python can be created using either double quotes (“) or single quotes (‘), providing flexibility in string declaration. For example:

print(‘Hello World!’)
OR
print(“Hello World!”)

Question 44

Why are there two variants for creating strings in Python? - (3)

Answer 44

Two variants for creating strings in Python, using single quotes (‘’) and double quotes (“), exist to allow the inclusion of single quotes quotes within strings without escaping.

This enhances code readability and simplicity

using double quotes (“) - you can then use the single quote in the string.

Question 45

Example of using single quotes in a string:

Answer 45

print(“Hello ‘World’”)

Output:
Hello ‘World’

Question 46

What is a string in Python?

Answer 46

In Python, a string is a sequence of characters enclosed within either single quotes (‘’) or double quotes (“”). It can consist of letters, numbers, symbols, or spaces.

Question 47

Print() function can take

Answer 47

a string as its argument and prints the content of the string to the standard output (usually the terminal or console)

Question 48

What is the purpose of the print function in the given Python code?

print(“Hello World!”)

Answer 48

The purpose of the print function in the code is to output the string “Hello World!” to the screen

Question 49

What happens when you execute the following Python code?

print(“jdkfjdlkfjdslfkjdslkf”) - (2)

Answer 49

Executing the code displays the string “jdkfjdlkfjdslfkjdslkf” on the screen.

The print function outputs the provided string of jdkfjdlkfjdslfkjdslkf to the output terminal/console

Question 50

What observation is made regarding the usage of quotation marks in the provided Python code?

Answer 50

In the code snippet, both single quotes (‘ ‘) and double quotes (“ “) are used to create strings.

Question 51

Identify the issue in the following Python code:

print(“Hello World!)

Answer 51

The issue in the code is the absence of a closing double quote, resulting in an “unterminated string literal” error.

Question 52

What error message is encountered when executing the given Python code?

print(“Hello World!)

Answer 52

The error message encountered is “unterminated string literal”, indicating that the provided string is not properly terminated with a closing double quote.

Question 53

How does the absence of a closing double quote affect the execution of the Python code?

print(“Hello World!)

Answer 53

The absence of a closing double quote results in an “unterminated string literal” error, halting the execution of the Python code due to a syntax error.

Question 54

Exercise
In the code box below, print the following strings:

It’s the best!

“Hi!” they said - (2)

Answer 54

print(“It’s the best!”)

print(‘“Hi!” they said’)

Question 55

What is the result of executing the following Python code?

print(“Hello” + “World”)

Answer 55

The result of executing the code is the concatenation of the two strings, resulting in the output “HelloWorld”.

Question 56

Explain the purpose of the + operator in the given Python code - (2)

print(“Hello” + “World”).

Answer 56

The + operator is used for string concatenation in the provided Python code.

It combines the strings “Hello” and “World” into a single string, “HelloWorld”.

Question 57

What action does the + operator perform when used with strings in Python?

e.g., print(“Hello” + “World”)

Answer 57

When used with strings in Python, the + operator concatenates or joins the strings together, producing a single string that contains the contents of both input strings.

Question 58

What is string concatenation in Python?

Answer 58

String concatenation involves joining two or more strings to form a single string, typically achieved using the + operator in Python.

Question 59

Why does Python not separate “Hello” and “World” in the code print(“Hello” + “World”)? - (2)

Answer 59

Python does not separate “Hello” and “World” because the + operator performs string concatenation, joining the two strings together into a single string.

Python does not know it is writing a sentence and does not know there should be a space between ‘Hello’ and ‘World’

Question 60

What happens if we don’t include a space between the strings in the code print(“Hello” + “World”)?

Answer 60

If we don’t include a space between the strings, Python will concatenate them without adding a space, resulting in “HelloWorld”.

Question 61

How can we include a space between the strings “Hello” and “World” in the code print(“Hello” + “World”)? - (5)

Answer 61

To include a space between the strings, we can add a space either in first string (adding space after the first word) , the second string (adding space before the second word), or as a third string with a space in between.

For example:

• print(“Hello “ + “World”)
• print(“Hello” + “ World”)
• print(“Hello” + “ “ + “World”)

these all give the same output

Question 62

What does the len() function do when applied to a string?

Answer 62

The len() function returns the number of characters in a string.

Question 63

What is the output of this code? - (3)

• print(“Hello “ + “World”)
• print(“Hello” + “ World”)
• print(“Hello” + “ “ + “World”)

Answer 63

Hello World
Hello World
Hello World

Question 64

What will the code print(len(“Hello World!”)) output?

Answer 64

The code will output the length of the string “Hello World!”, which is 12 (because of space and examination point)

Question 65

What arguments can you give to the len() function?

Answer 65

The len() function takes a single argument, which must be a sequence (such as a string, list, tuple, etc.), and returns the number of elements in that sequence.

Question 66

Can you give len() a variable as an argument?

Answer 66

Yes, you can pass a variable containing a sequence (such as a string, list, tuple, etc.) as an argument to the len() function.

Question 67

Functions take arguments (sometimes known as …. ) and gives you back (returns) something

Answer 67

parameters

Question 68

len() takes a single arguement and works out its length

It returns what length it is which we can either

Answer 68

print, put in a variable or otherwise use as appropriate.

Question 69

What does the following code snippet do: print(len(“Hello World!”))? - (2)

Answer 69

The len() function calculates the number of characters in the string “Hello World!”

This value is then passed to print() function which prints the result to the output console/terminal

Question 70

Explain the evaluation process of a nested function call like print(len(“Hello World”)) - (3)

Answer 70

Python evaluates the inner-most function call first, in this case, len(“Hello World”).

It calculates the length of the string “Hello World” and returns it.

Then, it evaluates the outer function call print(), which takes the returned value from the inner call and prints it to the screen.

Question 71

What is the output of the following code snippet?
myName = “Emma”
print(myName)
print(len(myName)) - (3)

Answer 71

The output is:
Emma
4

Question 72

What is a variable in programming?

Answer 72

A variable is a name for a value or an object in programming

Question 73

What do variables act like?

Answer 73

acts like a ‘box’ where data can be stored and manipulated

Question 74

How are variables assigned in Python?

Answer 74

Variables in Python are assigned using a single equals sign “=”.

Question 75

What is the output of the following code snippet?
msg = “Hello World”
print(msg) - (2)

Answer 75

The output is:
Hello World

Question 76

What does the following line of code do?
msg = “Hello World”
print(msg) - (2)

Answer 76

It assigns the string “Hello World” to the variable msg.

It prints the value stored in the variable msg.

Question 77

How is a variable defined in Python?

Answer 77

A variable is defined by using the assignment operator “=”, followed by the variable name and the value assigned to it.

Question 78

What are the rules for variable naming in Python? - (2)

Answer 78

Variable names can use letters, numbers, and underscores.

They are case sensitive (e.g., meaning that msg, Msg, and MSG are all considered different variables. ) and cannot start with a number.

Question 79

Can a variable name have a number in it in Python? - (2)

Answer 79

Yes, a variable name can have a number in it, but it cannot start with a number.

For example, myvar2 is a valid variable name, but 2myvar is not.

Question 80

Why should you avoid naming variables after Python keywords and standard functions?

Answer 80

Naming variables after Python keywords and standard functions can lead to confusion and errors in your code.

Question 81

What are some common sense guidelines for variable naming in Python? - (2)

Answer 81

Avoid using variable names that resemble numbers, such as ‘o’ or ‘O’, to prevent confusion with digits.

Additionally, be cautious when using ‘i’ and ‘l’ as they can be mistaken for ‘1’ in certain fonts.

Question 82

What are the two common ways of variable naming? - (2)

Answer 82

1. camelCase
2. use_underscores (sometimes called snake case)

Question 83

What is camelCase and how is it used in variable naming? - (2)

Answer 83

camelCase uses capital letters to indicate word boundaries in variable names/ use captial letters to show where variable names are:

Example: myVariable

Question 84

What is use_underscores (snake case) and how is it used in variable naming? - (2)

Answer 84

use_underscores, or snake case, involves using underscores between words in variable names.

Example: my_variable

Question 85

What happens when a variable is overwritten with a new value?

Answer 85

The original value of the variable is lost, and it holds the new assigned value.

Question 86

Can you retrieve the original value of a variable after it has been overwritten?

Answer 86

No, once a variable is overwritten with a new value, the original value is lost and cannot be retrieved.

Question 87

What is PEP8 and why is it important in Python programming? - (2)

Answer 87

PEP8 is a set of rules and guidelines for Python code style.

It helps ensure consistency and readability in Python code.

Question 88

What is the sequence of output when the following code is executed? - (3)

msg = “Hello World”
print(msg)

msg = “A new world”
print(msg)

Answer 88

The sequence of output is:

“Hello World”
“A new world”

Question 89

What happens when the following code is executed? - (4)

msg = “Hello World”
print(msg)

msg = “A new world”
print(msg)

Answer 89

The code first assigns the string “Hello World” to the variable msg and prints it.

Then, it assigns the string “A new world” to the same variable msg and prints it again. Therefore, the output will be:

Hello World
A new world

Question 90

What does the following code snippet do? - (4)

a = 2
b = 3

print(a * b)
print(a + b)

Answer 90

The code snippet assigns the integer value 2 to the variable a and the integer value 3 to the variable b.

Then, it prints the result of multiplying a and b, followed by printing the result of adding a and b. The output will be:

6
5

Question 91

What does the double equals sign (==) do in Python?

a) Assigns a value to a variable
b) Checks if two values are the same
c) Performs arithmetic addition
d) Evaluates an expression

Answer 91

b) Checks if two values are the same

Question 92

What does the following code snippet do? - (2)

a = 2
b = 3

print(a != b)

Answer 92

The code snippet prints True if the value of a is not equal to the value of b, and False otherwise.

Since a is 2 and b is 3, value of a is not equal to value of b thus returns False to output terminal/console

Question 93

What does the following code snippet do? - (5)

a = 2
b = 3

print(a * b)
print(a + b)

Answer 93

The code snippet assigns the integer value 2 to the variable a and the integer value 3 to the variable b.

Then, it prints the result of multiplying a and b, followed by printing the result of adding a and b.

The output will be:

6
5

Question 94

What does the del keyword do in Python?

a) Assigns a value to a variable
b) Deletes a variable from memory
c) Checks if two values are the same
d) Performs arithmetic addition

Answer 94

b) Deletes a variable from memory

Question 95

What does the following code snippet do? - (3)

b = 10
print(b)
del(b)
print(b)

Answer 95

The code snippet assigns the value 10 to the variable b and prints it.

Then, it deletes the variable b using the del keyword.

Attempting to print b after it has been deleted will result in a NameError because the variable no longer exists.

Question 96

As long as you are consistent with variable naming of camelCase and use_underscores it is

Answer 96

fine

Question 97

What does the == operator do in Python?

a) Assigns a value to a variable
b) Compares two values for equality
c) Deletes a variable from memory
d) Performs arithmetic addition

Answer 97

b) Compares two values for equality

Question 98

What is the purpose of the != operator in Python?

a) Assigns a value to a variable
b) Checks if two values are the same
c) Deletes a variable from memory
d) Compares two values for inequality

Answer 98

d) Compares two values for inequality

Question 99

Variables can be of

Answer 99

different types

Question 100

What are the important types of variables in Python?

a) int, str, bool, None
b) int, float, str, bool, None
c) int, float, str, bool
d) str, bool, None

Answer 100

b) int, float, str, bool, None

Question 101

What does the int type represent in Python? - (2)

a) Decimal numbers
b) Floating point numbers
c) Whole numbers
d) True or False values

Answer 101

c) Whole numbers

e.g., – can be positive or negative: … -2, -1, 0, 1, 2 …

Question 102

What are number variable types?

Answer 102

int and float

Question 103

What does the str type represent in Python? - (2)

a) Whole numbers
b) Decimal numbers
c) Floating point numbers
d) Zero or more characters

Answer 103

d) Zero or more characters

e.g., “Hello World”

Question 104

What does the bool type represent in Python?

a) Whole numbers
b) Decimal numbers
c) Floating point numbers
d) Boolean values - True or False values

Answer 104

d) Boolean values -True or False values

Question 105

What does the None type represent in Python?

a) Whole numbers
b) Floating point numbers
c) True or False values
d) Nothingness or absence of a value

Answer 105

d) Nothingness or absence of a value

Question 106

What does the type() function do in Python?

Answer 106

The type() function in Python is used to determine the data type of a variable or a value.

Question 107

What does the type() function return when given the argument 3?

Answer 107

The type() function returns <class ‘int’> when given the argument 3, indicating that 3 is an integer.

Question 108

What does the type() function return when given the argument 3.0?

Answer 108

The type() function returns <class ‘float’> when given the argument 3.0, indicating that 3.0 is a floating-point number.

Question 109

What does the type() function return when given the argument “3.0”?

Answer 109

The type() function returns <class ‘str’> when given the argument “3.0”, indicating that “3.0” is a string.

Question 110

What does the type() function return when given the argument None?

Answer 110

The type() function returns <class ‘NoneType’> when given the argument None, indicating that None represents the absence of a value.

Question 111

What does the type() function return when given the argument True or False?

Answer 111

The type() function returns <class ‘bool’> when given the arguments True or False, indicating that they are boolean values representing True or False, respectively.

Question 112

Instead of writing code like this with type() function, we can repeat same exercise but use variables like:

Answer 112

Question 113

Explain the behavior of type(float(3)) in Python.

Answer 113

The expression type(float(3)) converts the integer value 3 to a float and then determines its data type using the type() function.

Question 114

What is the purpose of type(int(3.25)) in Python?

Answer 114

The expression type(int(3.25)) converts the floating point number 3.25 to an integer and then checks its data type using the type() function.

Question 115

Describe the outcome of int(3.25) in Python.

Answer 115

The expression int(3.25) converts the floating point number 3.25 to an integer, resulting in the value 3.

Question 116

What is the result of int(3.999) in Python?

Answer 116

The expression int(3.999) converts the floating point number 3.999 to an integer, resulting in the value 3, as the conversion truncates the decimal part.

Question 117

What arithmetic operations can be performed on numbers in Python?

Answer 117

Arithmetic operations such as addition (+), subtraction (-), multiplication (*), division (/), integer division (//), exponentiation (**), and remainder (%) can be performed on numbers in Python

Question 118

Best to stick with one … data type in code

Answer 118

number data type like integers or floats

Question 119

Number data type of integer can be used for

Answer 119

no of people in group/particular exp condition or number of types someone blinked

Question 120

Number data type of float can be used for

Answer 120

reaction time e.g., 24.32 milliseconds (ms)

Question 121

What happens when executing print(3.0 + 3) in Python? - (3)

Answer 121

When running print(3.0 + 3), Python adds a floating point number (3.0) and an integer (3).

Python automatically converts the integer to a floating point number before performing the addition.

Forces the numbers to be same data type before performing addition.

Question 122

What is the output of print(3.999 + 3) in Python?

Answer 122

The output of print(3.999 + 3) is 6.999, as it performs addition between a floating point number (3.999) and an integer (3)

Question 123

Describe the outcome of print(3 - 2) in Python.

Answer 123

The outcome of print(3 - 2) is 1, which is the result of subtracting 2 from 3

Question 124

Note that python makes numbers

Answer 124

int by default unless they have a decimal point in them.

Question 125

An alternative of adding .0 at end of numbers, is - (2)

Answer 125

pass it through the float function.

This function takes a value as input and returns the corresponding floating point representation of that value.

Question 126

Describe the behavior of converting a floating point number to an integer using the int() function in Python. - (2)

Answer 126

When a floating point number is converted to an integer using the int() function in Python, the decimal part of the number is truncated, resulting in the loss of any fractional part.

This conversion does not round the number properly; instead, it simply removes the decimal part.

Question 127

What caution should be taken when converting floating point numbers to integers using the int() function in Python? - (2)

Answer 127

When converting floating point numbers to integers using the int() function in Python, it is important to note that the conversion truncates the decimal part, potentially leading to unexpected results.

This behavior can be a common source of bugs for new Python programmers, so caution should be exercised when using this method.

Question 128

Adding float to integer it will make it

Answer 128

float

Question 129

If you keep everything the same datatype when doing arithmetic operations in print statement e.g., print(3 + 2) it will remain the

Answer 129

same data type - integer in this case

Question 130

If you mix data types when doing arithmetic operations in print statement e.g., print(3.0 + 2) it will

Answer 130

typically become floating point values

Question 131

What is the difference between the two multiplication operations demonstrated in the code snippet? - (2)

print(3 * 2)

print(3.0 * 2)

Answer 131

The first multiplication operation (print(3 * 2)) involves multiplying two integers, resulting in an integer value.

In contrast, the second multiplication operation (print(3.0 * 2)) involves multiplying an integer and a floating point number, resulting in a floating point value.

Question 132

What is the output of print(3.0 * 2) in Python?

Answer 132

The output is 6.0.

Question 133

What is the output of print(3 * 2) in Python?

Answer 133

The output is 6.

Question 134

Explain the behavior of print(3.0 ** 3) in Python.

Answer 134

It computes the result of raising 3.0 to the power of 3, which equals 27.0.

Question 135

What does the expression print(9.0 ** 0.5) compute in Python?

Answer 135

It computes the square root of 9.0, which equals 3.0.

Question 136

How does the power operator () behave in Python? - (2)

Answer 136

The power operator () can be used to compute both “normal” power values, such as squaring, and roots.

For example, raising a number to 1/2 (0.5) computes the square root.

Question 137

How does division work in Python? - (2)

Answer 137

In Python, division is performed using the / operator.

It automatically converts integers to floating-point numbers ‘where necessary’.

Question 138

What is the result of print(3 / 2) in Python?

Answer 138

The expression print(3 / 2) evaluates to 1.5 because it performs floating-point division, resulting in a floating-point number.

Question 139

What does the // operator do in Python?

Answer 139

The // operator in Python performs integer division, discarding any fractional part and returning the integer result.

Question 140

What is the result of print(3//2) in Python?

Answer 140

The expression print(3//2) evaluates to 1 because it performs integer division, resulting in an integer quotient - has not rounded it (chopped off decimal part)

Question 141

What does the % (modulus) operator do in Python?

Answer 141

The % operator in Python returns the remainder of the division of the first number by the second number.

Question 142

What is the result of print(8 % 3) in Python?

Answer 142

The expression print(8 % 3) evaluates to 2 because when 8 is divided by 3, the remainder is 2.

Question 143

The ‘/’ allows integers to turn into

Answer 143

floating point numbers ‘where necessary’ (in other words if answer is not an integer)

Question 144

The ‘//’ does not allow

Answer 144

integers to turn to floating point numbers ‘where necessary’ (in other words if answer is not an integer)

Question 145

When using the integer division operator on floating point numbers, the division will be performed as if numbers were integer but result will be - (2)

Answer 145

floating point

e.g., print(3.0//2) in Python outputs the result of dividing 3.0 by 2 using integer division, resulting in 1.0.

Question 146

What happens when you try to add a string and an integer in Python

print(3 + “dlfkjdofd”),? - (2)

Answer 146

When you try to add a string and an integer in Python, you get a exception (error) TypeError because Python does not support adding different types together.

In the given example, print(3 + “dlfkjdofd”), Python raises an exception because you cannot concatenate a string and an integer directly.

Question 147

What type of error do you encounter when trying to add a string and an integer in Python?

Answer 147

When trying to add a string and an integer in Python, you encounter a TypeError.

Question 148

Question: What does the following code snippet do?

age_in_years = 21.5
days_in_year = 365
print(“My age in years is:”, age_in_years)
print(“My age in days in:”, age_in_years * days_in_year)

Answer 148

This code snippet sets up variables for age in years and days per year, then prints out the age in years followed by the age in days calculated by multiplying the age in years by the number of days in a year.

Question 149

What is it’s output? - (2)

age_in_years = 21.5
days_in_year = 365
print(“My age in years is:”, age_in_years)
print(“My age in days in:”, age_in_years * days_in_year)

Answer 149

My age in years is: 21.5
My age in days in: 7857.5

Question 150

What are the rules for precedence of mathematical operations in Python? - (3)

Answer 150

The rules for precedence of mathematical operations in Python follow roughly the same rules as those in mathematics.

Multiplication and division have higher precedence than addition and subtraction - BODMAS

e.g.., So, for instance: 1 + 2 * 3 will be evaluated as 1 + (2 * 3) giving a result of 7, because multiplication is higher precedence than addition.

Question 151

How can you ensure correct precedence in Python expressions or make code clearer?

Answer 151

You can use brackets to ensure correct precedence in Python expressions, similar to how you would in algebra.

Question 152

Give an example of using brackets to ensure correct precedence and making code clearer in Python.

Answer 152

res = (1 + 2) * 3
print(res)

Question 153

Can brackets be nested in Python expressions?

Answer 153

Yes, brackets can be nested in Python expressions for complex calculations.

Question 154

Provide an example of nested brackets in a Python expression.

Answer 154

res = 1 + (2 * (3 + 1))
print(res)

Question 155

res = (1 + 2) * 3
print(res)

Output and why? - (3)

Answer 155

9

In the first expression (1 + 2) * 3, the addition inside the parentheses is evaluated first, resulting in 3.

Then, the multiplication operation is performed, yielding 9.

Question 156

res = 1 + (2 * (3 + 1))
print(res)

output and why? - (3)

Answer 156

In the second expression 1 + (2 * (3 + 1)), the innermost parentheses (3 + 1) are evaluated first, resulting in 4.

Then, the multiplication operation 2 * 4 is evaluated, resulting in 8.

Finally, the outer addition 1 + 8 is performed, resulting in 9.