01 . Perform Operations using Data Types and Operations 1

Question 1

Describe what a variable is?

Answer 1

A variable can be thought of as a container that can store information that can be used later.

Question 2

Python has rules for how to declare a variable name.

List the four rules.

Answer 2

1. Variables cannot have spaces in the names
2. Variables are case-sensitive
3. Variables cannot start with a number. It must be either a letter or the underscore character.
4. A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )

Question 3

Name the best practice which should be used when declaring variables that contain two words.

Answer 3

The best practice is to use camel casing, i.e. firstName

Question 4

What type of variable is firstName in the given example?

firstName = ‘Bryce’

Answer 4

String variable

Question 5

A whole number is known as what type of variable in python?

Answer 5

An integer

Question 6

What punctuation symbols should we use to combine strings and numbers in a print statement?

Answer 6

A comma

Question 7

How many values does a Boolean variable have?

Answer 7

Two values - either True or False

Question 8

What will be the output in the print statement for the following code example?

north = 200

south = 300

northwins = north > south

southwins = south > north

print(“northwins = “, northwins, “\nSouthwins = “, southwins)

Answer 8

Note: the newline escape character on the previous slide. The output would be as follows.

northwins = False

southwins = True

Question 9

Are the two Boolean values case sensitive?

Answer 9

Yes - the values must be written either True or False.

Question 10

The following code example results in a TypeError when executed.

What function is required to cast the variable “widgets” to a string?

price = 3.95

widgets = 5

print(“The price of the widgets is “, price)

print(“We have “ + widgets + “ in stock.”)

Answer 10

Surround the variable widgets with the str function to cast it to a string.

print(“We have “ + str(widgets) + “ in stock.”)

Question 11

What type will the answer be as per the print statement calculation?

price = 3.95

widgets = 5

print(price * widgets)

Answer 11

It will be a float, i.e. 19.75

Question 12

What type of data structure is the following piece of code?

regions = [“North”, “South”, “East”, “West”]

Answer 12

Due to the square brackets, the sample code is a list.

Question 13

What method is required to add a new employee name to the end of the following list?

employee = [“Bob”, “Dave”, “John”]

Answer 13

The append() method.

employee.append(“Ken”)

Question 14

What method is required to remove an employee name from the following list?

employee = [“Bob”, “Dave”, “John”]

Answer 14

The remove() method

employee.remove(“Bob”)

Question 15

What method is required to arrange the names of the employees in alphabetical order?

employee = [“Bob”, “Dave”, “John”]

Answer 15

The sort() method

employee.sort()

Question 16

What index is “south” in the following list?

region = [“North”, “South”, “East”, “West”]

Answer 16

Index 1

Question 17

What will be the output from the following print statement?

region = [“North”, “South”, “East”, “West”]

print(“Region: “, region[-1])

Answer 17

Region: West

-1 can be used to access the last item in a list.

Question 18

What will be the print statement output in the following sample?

employees = [“Bob”, “Dave”, “John”]

employees[2] = “Michael”

for employee in employees:
print(employee)

Answer 18

Bob
Dave
Michael

The index value of 2 represents the last item in the list. Therefore, the item for John will be overwritten with the name Michael.

Question 19

What data type is the variable in the following code example?

serialNumber = “535353”

Answer 19

A string variable.

Question 20

What data type is the variable in the following code example?

itemsReceived = False

Answer 20

A Boolean variable