Lesson 4 homework

One program, grown four times. You'll start from the names list in the lesson and turn it into a little roster manager — a tool that prints the team, adds players, removes them, and swaps them out. Each problem is the last one plus one new idea.

Work like a programmer on each one:

Write the pseudocode in English first
Run it in your head before you run it in Python
Translate line by line — every piece is something from the lesson or the reading
Make as many mistakes as you like
Don't give up

Start every problem from this list:

names = ["scott", "rish", "tom", "jerry", "john"]

Problem 1 — number the roster

Print every player with its index in front, so you can see the position numbers you'll need later.

Output

0 scott
1 rish
2 tom
3 jerry
4 john

Code

This is the "watch the numbers change" loop from the end of the lesson: for i in range(len(names))
Inside, print two things on one line — the index i and names[i]. Commas in print put a space between them for free

Problem 2 — add and remove, safely

Ask the user for a name to add, then a name to remove. Print the whole list after each change.

Output (the user typed mo, then tom)

player to add: mo
['scott', 'rish', 'tom', 'jerry', 'john', 'mo']
player to remove: tom
['scott', 'rish', 'jerry', 'john', 'mo']

Code

input gets the name, append adds it, remove deletes it — all straight from the lesson
One trap: remove crashes if the name isn't in the list (you saw the ValueError in the reading). Guard it — only remove if the name in names, otherwise print something friendly like no such player
Bonus: guard the add the same way, so you don't append a name that's already on the team

Problem 3 — swap a player

Ask the user for an index and a new name, then replace the player at that index. Print the list.

Output (the user typed 2, then tommy)

which index to swap? 2
new name? tommy
['scott', 'rish', 'tommy', 'jerry', 'john']

Code

Changing an item in place is names[i] = new_name — the mutable-list idea from the reading
Remember input gives a string; the index has to be a number, so int(...) it — like the calculator in Lesson 1
Guard the index with len, exactly like the lesson: only swap if the index < len(names), otherwise print no such index. A careless 9 should print a message, not crash

Problem 4 — the roster table (stretch)

Give every player a jersey number by turning the roster into a list of lists:

players = [
    ["scott", 7],
    ["rish", 10],
    ["tom", 4],
    ["jerry", 23],
    ["john", 15]
]

Ask the user for an index and print a sentence about that player.

Output (the user typed 1)

which player? 1
rish wears number 10

Code

Each row is itself a list, so you index twice: players[i][0] is the name, players[i][1] is the number
Build the sentence with an f-string from the Lesson 3 reading: f"{players[i][0]} wears number {players[i][1]}"
Guard the index with len again — same safe habit as Problem 3

When all four run, look at them side by side: one list, and a whole tool built out of the handful of moves from this week — loop, append, remove, names[i] = ..., and a len guard on every risky reach. That's a real program.