Model a Playlist with Track Components

Summary

Build a Playlist class composed of Track objects and implement common playlist behaviors using composition.

Problem statement

You will model a simple music playlist using composition. Implement two classes: Track and Playlist. A Track represents a single song with a title, artist, duration (in seconds), and optional album. A Playlist contains Track instances and provides operations to add and remove tracks, compute durations, and search by artist. Required Playlist methods: - add_track(track): add a Track to the end of the playlist. - total_duration(): return the total duration in seconds (int) of all tracks in the playlist. - track_titles(): return a list of track titles in playlist order. - find_by_artist(artist): return a list of titles of tracks by the given artist, preserving playlist order. - remove_track(title): remove the first track matching title; return True if removed, False if not found. - average_duration(): return the average track duration as a float rounded to 2 decimals; return 0.0 for an empty playlist. Design the classes so Playlist stores Track objects (composition) rather than copying track data around.

Task

Practice design using composition: create Track and Playlist classes and implement methods that operate on composed Track instances.

Examples

Input format

Functions and methods will be called directly in tests (e.g., create_playlist([...]).total_duration()).

Output format

Return values: ints, lists of strings, booleans, or floats (converted to string by the test harness).

Constraints

Do not use external libraries. Preserve playlist order for title lists and searches. average_duration must return 0.0 when the playlist has no tracks.

Samples