Auto Driving Car Simulation

A Python simulation of autonomous cars moving on a bounded rectangular field. Cars execute F/L/R command sequences simultaneously, step by step. Collisions are detected after every step and colliding cars are stopped immediately.

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Requirements

• Python 3.12+

python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"

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Running the simulation

There are two interfaces: an interactive CLI and a batch (pipe/file) mode.

Interactive CLI

Step-by-step prompts guide you through field setup, car registration, and running the simulation.

python -m src.cli

Example session:

Welcome to Auto Driving Car Simulation!
Please enter the width and height of the simulation field in x y format:
10 10
You have created a field of 10 x 10.
Please choose from the following options:
[1] Add a car to field
[2] Run simulation
1
Please enter the name of the car:
A
Please enter initial position of car A in x y Direction format:
1 2 N
Please enter the commands for car A:
FFRFFFFRRL
Your current list of cars are:
- A, (1,2) N, FFRFFFFRRL
Please choose from the following options:
[1] Add a car to field
[2] Run simulation
2
Your current list of cars are:
- A, (1,2) N, FFRFFFFRRL
After simulation, the result is:
- A, (5,4) S
Please choose from the following options:
[1] Start over
[2] Exit
2
Thank you for using Auto Driving Car Simulation!

Batch mode (stdin pipe or file argument)

Reads the full scenario from stdin or a file and prints results to stdout.

# Pipe from stdin
printf "10 10\nA 1 2 N FFRFFFRRLF" | python -m src.simulation

# Read from a file
python -m src.simulation scenario.txt

Input format

<width> <height>
<name> <x> <y> <direction> <commands>
<name> <x> <y> <direction> <commands>
...

Field	Description
width	Positive integer — number of columns (x: 0 … width−1)
height	Positive integer — number of rows (y: 0 … height−1)
name	Unique car identifier (no spaces)
x, y	Initial position — integers within field bounds
direction	Initial heading — one of N, S, E, W
commands	Non-empty string of F (forward), L (left), R (right)

The coordinate origin (0, 0) is the bottom-left corner. x increases eastward; y increases northward.

A car that reaches a boundary wall ignores the F command and stays put. A car that exhausts its commands holds its final position for the remaining steps.

Output format

Collision records are printed first (in step order, then by position), followed by surviving cars in declaration order.

# Collision record (one line per collision group)
A B collides at (2,2) at step 1

# Survivor record
A (4,3,S)

Examples

Single car — no collision:

printf "10 10\nA 1 2 N FFRFFFRRLF" | python -m src.simulation
# A (4,3,S)

Two cars — head-on collision:

printf "10 10\nA 1 2 E FFF\nB 3 2 W FFF" | python -m src.simulation
# A B collides at (2,2) at step 1

Three cars — two collide, one survives:

printf "10 10\nA 0 2 E FFFFF\nB 4 2 W FFFFF\nC 0 9 S F" | python -m src.simulation
# A B collides at (2,2) at step 2
# C (0,8,S)

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Project structure

src/
  field.py        — Field class: dimensions + bounds checking
  car.py          — Car class: position, direction, command execution
  collision.py    — detect_collisions(): collision detection; CollisionEvent dataclass
  simulation.py   — Simulation class + batch CLI entry point
  cli.py          — CliSession: interactive CLI entry point

tests/
  test_field.py           — Field unit tests
  test_car.py             — Car unit tests
  test_collision.py       — detect_collisions() / CollisionEvent unit tests
  test_cli_field.py       — CLI field-setup prompt unit tests
  test_cli_car.py         — CLI car-registration flow unit tests
  test_cli_run.py         — CLI run-and-result unit tests
  test_cli_e2e.py         — Full interactive session end-to-end tests

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Running tests

python -m pytest

All 134 tests should pass:

...........................................................................
134 passed in 0.5s

For verbose output with short tracebacks on failure (the default via pyproject.toml):

python -m pytest -v --tb=short