CS: Python: Lists and Basic Functions
Practice using lists, indexes, loops, parameters, and return values
CS: Python: Lists and Basic Functions
Practice using lists, indexes, loops, parameters, and return values
CS - Grade 6-8
- 1
A Python list is written as scores = [85, 92, 78, 90]. What value is at index 1, and why?
Count positions starting with 0, not 1.
The value at index 1 is 92 because Python list indexes start at 0, so index 0 is 85 and index 1 is 92. - 2
What does this code print? animals = ['cat', 'dog', 'bird']; print(animals[2])
The code prints bird because 'bird' is the item at index 2 in the list. - 3
Write one line of Python code that adds the string 'grape' to the end of this list: fruits = ['apple', 'banana']
Use the list method that adds one item to the end of a list.
One correct line is fruits.append('grape'). This adds 'grape' to the end of the fruits list. - 4
What is the final value of nums after this code runs? nums = [1, 2, 3]; nums.append(4); nums.append(5)
The final value of nums is [1, 2, 3, 4, 5] because append adds each new item to the end of the list. - 5
What does this code print? names = ['Ava', 'Ben', 'Mia', 'Leo']; print(len(names))
The len function counts items, not letters.
The code prints 4 because len(names) counts the number of items in the list. - 6
Write a function called greet that takes one parameter called name and returns the message 'Hello, ' plus the name.
Use a parameter inside the return statement.
One correct answer is def greet(name): return 'Hello, ' + name. For example, greet('Sam') returns 'Hello, Sam'. - 7
What does this code print? def double(x): return x * 2; print(double(6))
The code prints 12 because the function returns 6 multiplied by 2. - 8
Write a function called first_item that takes a list called items and returns the first item in the list.
Use index 0 to get the first item.
One correct answer is def first_item(items): return items[0]. This works because the first item in a Python list is at index 0. - 9
What does this code print? colors = ['red', 'green', 'blue', 'yellow']; print(colors[1:3])
In a slice, the ending index is not included.
The code prints ['green', 'blue'] because the slice starts at index 1 and stops before index 3. - 10
Write a function called count_items that takes a list called things and returns how many items are in the list.
One correct answer is def count_items(things): return len(things). This returns the number of items in the list. - 11
What does this code print? nums = [3, 5, 7]; total = 0; for n in nums: total = total + n; print(total)
Track how total changes each time through the loop.
The code prints 15 because the loop adds 3, then 5, then 7 to the total. - 12
Write a function called sum_list that takes a list of numbers called nums and returns the sum of all numbers in the list using a for loop.
Start with total = 0, then add each number inside the loop.
One correct answer is def sum_list(nums): total = 0; for n in nums: total = total + n; return total. The function adds each number to total and returns the final sum. - 13
Find and fix the error in this code: def add_one(x): x + 1; print(add_one(4))
The function is missing a return statement. A fixed version is def add_one(x): return x + 1; print(add_one(4)). This prints 5. - 14
What is the difference between print and return in a Python function? Give a short explanation.
Think about whether the value is only displayed or actually given back to the program.
print shows a value on the screen, but return sends a value back from the function so the program can use it later. - 15
Write a function called bigger_than_five that takes a list of numbers and returns a new list containing only the numbers greater than 5.
Use an empty result list, an if statement, and append.
One correct answer is def bigger_than_five(nums): result = []; for n in nums: if n > 5: result.append(n); return result. This creates a new list and adds only the numbers greater than 5.