TAC 115 Midterm 2

What is a string (str)?

Text inside quotes (e.g., "hello"); used to store words or characters; immutable (cannot be changed)

What is an int?

A whole number (e.g., 5, -3); no decimals

What is a float?

A number with a decimal (e.g., 3.14, -0.5)

What is a bool?

A data type with only two values: True or False

What is a list?

A collection of multiple values stored in order using brackets (e.g., [1, 2, 3]); mutable

What is a for loop?

A loop that repeats code a specific number of times using a sequence like range()

Does a for loop repeat based on a condition?

False; it repeats based on a sequence, not a condition

What does list.append() do?

Adds a new value to the END of a list

The list.append() method adds a value to the end of a list

True

Do function names have to start with a letter or underscore?

Yes; they cannot start with numbers

What does str.join() do?

Combines elements of a list into a single string using a separator

The str.join() method will turn a string into a list

False; it turns a list into a string

Lists are immutable (not changeable)

False; lists are mutable and can be changed

What is a boolean expression?

An expression that evaluates to either True or False (e.g., 5 > 3)

What is str.isalnum()?

Returns True if all characters in the string are letters or numbers (no spaces/symbols)

What is len()?

Returns the number of items in a list or characters in a string

What does show[index] do?

Accesses the value at a specific position in a string or list (index starts at 0)

What does random.choice() do?

Returns a random element from a list

How do you know the value of a variable?

Look at what is assigned using = or trace the code step-by-step

What does del do?

Deletes an item at a specific index in a list (e.g., del list[0])

What does list.pop() do?

Removes and returns an item at a specific index (default is last item)

What does list.remove() do?

Removes the first occurrence of a specific value from a list

What does list.index() do?

Returns the index (position) of a specified value

What does list.sort() do?

Sorts the list in place (changes original list)

What does sorted() do?

Returns a NEW sorted list without changing the original

What does range() do?

Generates a sequence of numbers used in loops (start, stop, step)

What does range(3) return?

0, 1, 2

What does range(5, 6) return?

5

What does range(1, 10, 2) return?

1, 3, 5, 7, 9

What is an infinite loop?

A loop that never ends because the condition is always True

What is a while condition?

The condition that controls whether the loop continues running

What is a while loop?

A loop that repeats as long as a condition is True

Difference between "and" and "or"

"and" requires BOTH conditions to be True; "or" requires at least ONE to be True

What does += mean?

Adds a value and assigns it back to the variable (x += 1 means x = x + 1)

What does a for condition do?

Controls how many times the loop runs by defining the sequence (range)

What does a for loop do?

Repeats a block of code for each value in a sequence

What does def do?

Defines (creates) a function

What does main() do?

A function used as the starting point of a program; calls other functions

What does \n do?

Creates a new line when printing text

What does input() return?

Always returns a string

How do you convert input to an integer?

Use int(input())

What is indexing?

Accessing elements using positions starting at 0 (first element is index 0)

What is slicing?

Getting a portion of a list/string using [start]; stop is NOT included

What happens if you go out of index range?

IndexError occurs (program crashes)

What does "in" do?

Checks if a value exists in a list or string (returns True/False)

What does not do?

Reverses a boolean value (True becomes False, False becomes True)