Python Exercises: Lists & Loops

These exercises are designed to help you practice working with lists and loops in Python.

Cheat sheets if you need to look up any Python commands.

https://github.com/phil-lewis-exe/PythonCheatSheets/blob/main/Week1_cheatsheet.md

https://github.com/phil-lewis-exe/PythonCheatSheets/blob/main/Week2_cheatsheet.md

---

TASKS

Part 1: Accessing Elements

Create a new code file called workshop2b_part1.py

Start the file with the following lines of code:

print("Part 1:")
letters = ['a', 'b', 'c', 'D', 'x', 'f', 'g', 'y' ]

i. Use print(letters) to display the full list.

ii. Access and print the first element of the list.

iii. Access and print the third element of the list.

iv. Access and print the last element of the list using negative indexing.

Run the file and check the code output, it should be:

Part 1:
['a', 'b', 'c', 'D', 'x', 'f', 'g', 'y']
a
c
y

---

Part 2: Modifying, Adding & Removing Elements

Create a new code file called workshop2b_part2.py

Start the file with the following lines of code:

print("Part 2:")
letters = ['a', 'b', 'c', 'D', 'x', 'f', 'g', 'y' ]

Now add code lines to do the following.

i. Change the letter 'D' at index 3 to a lowercase 'd'. Print the list to see the change.

ii. Insert the letter 'z' at the beginning of the list (index 0). Print the list.

iii. Use the pop() method to remove the last letter from the list. Print the popped letter.

iv. Print the modified list after the pop operation.

v. Add the letter 'h' to the very end of the list. Print the list.

vi. Use the .index() method to locate the element 'x' and store its index in a variable idx. Print the value of idx.

vii. Use the del statement and the idx variable to remove 'x'. Print the modified list.

viii. Use the remove() method to find and remove the letter 'z'. Print the final list.

Run the file and check the code output, it should be:

Part 2:
['a', 'b', 'c', 'd', 'x', 'f', 'g', 'y']
['z', 'a', 'b', 'c', 'd', 'x', 'f', 'g', 'y']
y
['z', 'a', 'b', 'c', 'd', 'x', 'f', 'g']
['z', 'a', 'b', 'c', 'd', 'x', 'f', 'g', 'h']
5
['z', 'a', 'b', 'c', 'd', 'f', 'g', 'h']
['a', 'b', 'c', 'd', 'f', 'g', 'h']

---

Part 3: Organizing a List

Create a new code file called workshop2b_part3.py

Start the file with the following lines of code:

print("Part 3:")
letters = ['f', 'g', 'd', 'c', 'e', 'a', 'b']

i. Print the total number of items (the length) in the letters list.

ii. Use the reverse() method to permanently reverse the list. Print the list to confirm the new order.

iii. Use the sorted() function to print the list in alphabetical order without changing the original list.

iv. Print the letters list again to show it was not changed.

v. Use the sort() method with reverse=True to permanently sort the list in reverse-alphabetical order. Print the list.

Run the file and check the code output, it should be:

Part 3:
7
['b', 'a', 'e', 'c', 'd', 'g', 'f']
['a', 'b', 'c', 'd', 'e', 'f', 'g']
['b', 'a', 'e', 'c', 'd', 'g', 'f']
['g', 'f', 'e', 'd', 'c', 'b', 'a']

---

Part 4: Slicing

Create a new code file called workshop2b_part4.py

Start the file with the following lines of code:

print("Part 4:")
letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g']

i. Create a slice that contains the first four letters of the list (['a', 'b', 'c', 'd']). Print it.

ii. Create a slice that contains the letters 'd', 'e', and 'f'. Print it.

iii. Make a copy of the entire letters list using a slice. Print the copy.

Run the file and check the code output, it should be:

Part 4:
['a', 'b', 'c', 'd']
['d', 'e', 'f']
['a', 'b', 'c', 'd', 'e', 'f', 'g']

---

Part 5: Looping

This section uses some code to run loops you may not have seen before (e.g. the enumerate function).

Check the cheat sheet to see an example on how to use it.

Create a new code file called workshop2b_part5.py

Start the file with the following line of code:

print("Part 5:")

i. Create a list called list_one containing ['h', 'i', 'j', 'k', 'l'].

Use a for loop and range() to loop over and print the first four items from list_one.

ii. Create a list called list_two containing ['m', 'n', 'o'].

Use a for loop with the in keyword to loop over and print all the items in list_two.

iii. Create a list called list_three containing ['p', 'q', 'r', 's'].

Use enumerate() in a for loop to print the index and the letter in this format: 0: p.

Run the file and check the code output, it should be:

Part 5:
h
i
j
k
m
n
o
0: p
1: q
2: r
3: s