Chapter 3 : Phython Codes

Question 1

What is a data structure

Answer 1

A data structure s a special kind of variable that can hold serveral values.

Question 2

Give 3 examples of storing data values

Answer 2

• Social media platforms storing data on all the different accounts.
• A team manager who wants to store data on all his team players.
• A busniess owner storing data on all their products

Question 3

What does traversing mean?

Answer 3

To look at every value on a data structure

Question 4

Name 2 reasons people might want to traverse data

Answer 4

• A team manager wants to send an email to all its players
• Social Media platofrm wants to know which accounts are online and which are offline.

Question 5

How can a user change the size of a list?

Answer 5

• Append a value to make the list longer
• Delete a value to make the list shorter

Question 6

What happens if the stop value doesnt match the size of the list?

Answer 6

It will either end too early, missing a few values or it will go on for too long, causing an out of bounds error.

Question 7

Phython code for traversing a list

Answer 7

topiclist = [“A”, “B”, “C”]
for i in range [3] :
print (i, topiclist[i])

Question 8

Phython code for finding the list length

Answer 8

topiclist = [“A”, “B”, “C”]
stop = len(topiclist)
for i in range (stop) :
print (i, topiclist[i])

Question 9

What is a program interface?

Answer 9

The part of the program that handles input and output.

Question 10

Name 5 requirments for a program interface

Answer 10

• Tell the user what the program is and what does it do
• Allow the user to exit the program
• Allow the user to enter an input
• Let the user make choices or select options
• Display results or answers

Question 11

What is the error in this program?

topiclist = []
choice == “X”
while choice == “X” :
print(T O P I C S)
print(===================)
print(“\n”)
print(“A: Append a value”)
print(“B: Print the teamlist”)
print(“X: Exit the Program”)

Answer 11

The wrong logical test is used.

It should be != instead of ==

Question 12

What is the error in this program?

topiclist= []
while choice != “X” :
print(T O P I C S)
print(===================)
print(“\n”)
print(“A: Append a value”)
print(“B: Print the teamlist”)
print(“X: Exit the Program”)
choice = input(“Enter your choice: “)

Answer 12

Choice is not defined as it has not been given a value yet.

Question 13

What is the error in this program?

choice = “ “
while choice != “X” :
topiclist []
print(T O P I C S)
print(===================)
print(“\n”)
print(“A: Append a value”)
print(“B: Print the teamlist”)
print(“X: Exit the Program”)
choice = input(“Enter your choice: “)

Answer 13

The topiclist is inside the loop. Whenever the loop is repeated, the topiclist will be cleared and go back to being empty.

Question 14

What is nesting?

Answer 14

When a program structure is inside of another structure.

Question 15

What is the command to print an element?

Answer 15

i = input (“Which list item do you want to print?”)
i = int(i)
print (topiclist[i])

Question 16

What is the command to edit an element?

Answer 16

i = input (“Which list item do you want to edit?”)
i - int(i)
teamlist[i] = input (“Enter a new value.”)

Question 17

What is the command to delete an element?

Answer 17

i = input (“Which list item do you want to delete?”)
i - int(i)
del topiclist[i]

Question 18

What is the full program using double indentation?

Answer 18

teamlist = []
choice = “ “

while choice != “X” :
print(“ T O P I C S”)
print(“=======================”)
print(“This list will show you all the topics”)
print(“\n”)
print(“A: Append a value”)
print(“B: Print the topic list”)
print(“X: Exit the program”)

if choice == “A” :
topic = input(“Enter a new topic”)
topiclist.append(topic)

if choice == “B” :
print(topiclist)