pdf week 2

Question 1

What do conditionals allow in programming?

Answer 1

Conditionals allow a program to make decisions based on certain conditions, like choosing a path based on user input

Question 2

Give examples of when conditionals are useful.

Answer 2

When a user inputs wrong data (e.g., expecting an integer but receiving text).
When reaching the end of a file.
After a sufficient number of actions are performed (e.g., printing numbers from 1 to 10).

Question 3

>

Answer 3

greater than

Question 4

<

Answer 4

less than

Question 5

> =

Answer 5

greater than or equal to

Question 6

<=

Answer 6

less than or equal to

Question 7

==

Answer 7

equals to

Question 8

!=

Answer 8

not equal to

Question 9

What is control flow?

Answer 9

Control flow refers to the order in which individual statements, instructions, or function calls are executed in a program.

Question 10

How does elif improve the efficiency of conditional statements?

Answer 10

elif allows the program to skip subsequent checks once a true condition is found, reducing unnecessary evaluations.

Question 11

Why use an else statement?

Answer 11

An else statement provides a default action when none of the preceding conditions are met, simplifying logic.

Question 12

What does the or operator do?

Answer 12

The or operator allows the program to evaluate multiple conditions, executing the code block if at least one condition is true.

Question 13

What does the and operator do?

Answer 13

The and operator requires all conditions to be true for the code block to execute.

Question 14

What is short-circuit evaluation?

Answer 14

In short-circuit evaluation, if the first condition of an and or or statement determines the outcome, the second condition is not evaluated.

Question 15

What are nested conditionals?

Answer 15

Nested conditionals are conditionals placed inside other conditionals, allowing for more complex decision-making.

Question 16

How can conditionals be used with strings?

Answer 16

You can compare strings, check for the presence of substrings, and manipulate strings based on conditions (e.g., modifying case, stripping whitespace).

Question 17

What is short-circuit evaluation in programming?

Answer 17

Short-circuit evaluation means that in logical expressions, not all parts of the expression need to be evaluated if the result can be determined early.

Question 18

How does short-circuit evaluation work with the and operator?

Answer 18

If the first expression connected by and evaluates to False, the entire compound expression is False without evaluating the second expression.

Question 19

How does short-circuit evaluation work with the or operator?

Answer 19

If the first expression connected by or evaluates to True, the entire compound expression is True without evaluating the second expression.

Question 20

How do you check for equality in Python?

Answer 20

Use == to check if two strings are equal, e.g., “test” == myString.

Question 21

How do you check if two strings are not equal?

Answer 21

Use !=, e.g., “test” != myString.

Question 22

What does the equality comparison return?

Answer 22

It returns a boolean value: True or False.

Question 23

How does the equality comparison work?

Answer 23

It checks one character at a time from left to right.

Question 24

How do you check if a substring exists in a string?

Answer 24

Use in, e.g., “test” in myString.

Question 25

How do you check if a substring does not exist in a string?

Answer 25

Use not in, e.g., "test" not in myString.

Question 26

How can you find the number of characters in a string?

Answer 26

Use len(myString) to get the length.

Question 27

How do you convert a string to upper case?

Answer 27

Use .upper(), e.g., myString.upper().

Question 28

How do you convert a string to lower case?

Answer 28

Use .lower(), e.g., myString.lower().

Question 29

How do you remove leading and trailing whitespace from a string?

Answer 29

Use .strip(), e.g., myString.strip().

Question 30

How do you replace a part of a string with another?

Answer 30

Use .replace("target", "replacement"), e.g., myString.replace("target", "replacement").

Question 31

How do you start using random number generation in Python?

Answer 31

Import the random module at the beginning of your program: import random.

Question 32

How do you generate a random floating point number?

Answer 32

Use random.random(), which generates a value between [0.0, 1.0)

Question 33

How do you generate a random integer between two values?

Answer 33

Use random.randint(val1, val2), which generates an integer in the range [val1, val2].

Question 34

What type of values are required for random.randint(val1, val2)?

Answer 34

Both val1 and val2 must be integer values.

Question 35

How do you generate a random float between two specified values?

Answer 35

Use random.uniform(val1, val2), which generates a floating point value between [val1, val2].

Question 36

How do you generate a random integer between 0 and a specified value?

Answer 36

Use random.randrange(val1), which generates an integer in the range [0, val1).

Question 37

How do you generate a random integer between two specific values using randrange?

Answer 37

Use random.randrange(val1, val2), which generates an integer in the range [val1, val2).

Question 38

How can you generate a random integer with a specific step interval?

Answer 38

Use random.randrange(val1, val2, val3), which generates an integer in the range [val1, val2) with a step of val3.