Parking Lot

Project Structure

Majorly has three parts:

1. config : Env specific configurations with COMMAND_DICT in common.py which is a map of expected of commands
2. parking_system : Parking system package with core parking logic and required mappings
   • constants.py : All constants related to parking system
   • driver.py : Driver class with age attribute
   • exceptions.py : Custom execptions related to parking system
   • main.py : RunParkingSystem class to run logics according to input commands. Basically a pythonic switch-case
   • parking_system.py : Singleton design pattern based parking system class. Includes all the logics required to park or leave a car. Car assignment is done with min-heap data structure
   • utils.py : Utility class for helper methods
   • vehicles.py : Vehicle base class and its sub classes
3. run.py : Script to run the parking system algorithm

Getting started

• Clone the project and cd parking_system/
• Requirements : Python3.6+

Shell

• run.sh : Executes user command and run parking system algorithm
  • Configure PARKING_SYSTEM_ENV according to required environment. Default is production
  • To trace more detailed logs configure PARKING_SYSTEM_ENV to development or pre-production
• Give permissions : sudo chmod +x run.sh
• Run from filepath : ./run.sh filepath=./files/input.txt. Change filepath for your requirement
• Run interactively on terminal ./run.sh interactive

Console Output

Python

• Default environment : development
• Run from filepath :python run.py --filepath=./files/input.txt. Change filepath for your requirement
• Run interactively on terminal: python run.py --interactive

Design Thoughts

• Used singleton design pattern for ParkingSystem class. Only one instance of ParkingSystem will be available all the time. I chose not to raise exception and exit the system because may be real-world scenario that is not feasible rather I recreate instance with with new params on same address.
• For car parking logics used min-heap data structure LOG_LEVEL is INFO and for pre-production/development as DEBUG. To change the env export PARKING_SYSTEM_ENV=xxxx.
• Created Vehicle base class and extends car from it so that the system can be scaled in future for other vehicle types as well
• Kept checks on input command outside parking_system package. helper.py verifies the command validity and number of params for a particular command and main.py gives the interface between input command and parking system package