A replit db example

main.py

"""
https://replit.com/@TimelessP/Replit-db-experiment#main.py
https://gist.github.com/TimelessP/72f4efa1e5b523df526ff9cf3c7de4da
"""
from replit import db
from dataclasses import dataclass
import bcrypt
import getpass
import re
import datetime
import random
import time
import json


@dataclass
class User:
  username: str
  password_hash: str
  ctime_utc: datetime.datetime
  atime_utc: datetime.datetime
  mtime_utc: datetime.datetime
  is_disabled: bool = False

  def __init__(self,
               username: str,
               password_hash: str,
               ctime_utc: datetime.datetime,
               atime_utc: datetime.datetime,
               mtime_utc: datetime.datetime,
               is_disabled: bool = False):
    self.username = username
    self.password_hash = password_hash
    self.ctime_utc = ctime_utc
    self.atime_utc = atime_utc
    self.mtime_utc = mtime_utc
    self.is_disabled = is_disabled

  def to_dict(self):
    return {
      'username': self.username,
      'password_hash': self.password_hash,
      'ctime_utc': self.ctime_utc.isoformat(),
      'atime_utc': self.atime_utc.isoformat(),
      'mtime_utc': self.mtime_utc.isoformat(),
      'is_disabled': self.is_disabled
    }

  @classmethod
  def from_dict(cls, data):
    return cls(username=data['username'],
               password_hash=data['password_hash'],
               ctime_utc=datetime.datetime.fromisoformat(data['ctime_utc']),
               atime_utc=datetime.datetime.fromisoformat(data['atime_utc']),
               mtime_utc=datetime.datetime.fromisoformat(data['mtime_utc']),
               is_disabled=data['is_disabled'])


# db.clear()
db["inited"] = True


class Game:

  def __init__(self):
    self.username = None
    self.is_exiting = False
    self.action_handlers = {
      "exit": self._exit_game,
      "help": self._help,
      "id": self._user_id,
      "reset": self._reset,
      "users": self._users_list,
    }

  def run(self):
    while True:
      self.is_exiting = False
      time.sleep(random.uniform(0, 1))
      print("")
      print("Welcome to the demo. Use demo/demo for a demo user.")
      username = input("Enter your username: ")
      if not re.search(r"^[a-z][a-z0-9]{2,15}$", username):
        print(
          "Invalid username. Usernames must be lowercase a-z, 0-9, from 3 to 16 characters long, and cannot start with a number."
        )
      password = getpass.getpass(prompt="Enter your password: ")

      if not db.get("user." + username, default=None):
        confirm_password = getpass.getpass(prompt="Confirm your password: ")
        if password == confirm_password:
          hashed_password = bcrypt.hashpw(password.encode(), bcrypt.gensalt())
          user = User(username, hashed_password.decode(),
                      datetime.datetime.utcnow(), datetime.datetime.utcnow(),
                      datetime.datetime.utcnow())
          db.set(f'user.{username}', json.dumps(user.to_dict()))
          print(f"Welcome {username}! You have been added as a new user.")
        else:
          print("Passwords do not match. Please try again.")
          continue
      else:
        user = json.loads(db.get(f'user.{username}'),
                          object_hook=User.from_dict)

        if bcrypt.checkpw(password.encode(), user.password_hash.encode()):
          print(f"Welcome back {username}!")
        else:
          print("Incorrect password. Please try again.")
          continue

      self.username = username
      self.main()
      self.username = None

  def main(self):
    while not self.is_exiting:
      print("")
      activity, *args = input(f"{self.username}> ").strip().split() or ("", )

      if not activity.strip():
        continue

      for action, handler in self.action_handlers.items():
        if action.startswith(activity):
          handler(*args)
          break
      else:
        print("Invalid action. Enter `help` for valid actions.")

  def _reset(self, *args, **kwargs):
    db.clear()
    self.is_exiting = True
    print("All users removed.")

  def _users_list(self, *args, **kwargs):
    for user in db.prefix("user."):
      print(re.sub(r"^user[.]", "", user))
      continue

  def _exit_game(self, *args, **kwargs):
    self.is_exiting = True

  def _help(self, *args, **kwargs):
    print("Valid actions")
    actions_list = ", ".join(self.action_handlers.keys())
    print("\t" + actions_list if actions_list else "(none)")

  def _user_id(self, *args, **kwargs):
    if args and not db.get(f'user.{args[0]}', default=None):
      print("Unknown username.")
      return

    user = json.loads(db.get(f'user.{args[0] if args else self.username}'),
                      object_hook=User.from_dict)

    print(user)


if __name__ == "__main__":
  if not db:
    print("You need to be signed in to replit.com to use this app.")
    print("The data you persist will only be visible to your account.")
    exit(1)

  game = Game()
  game.run()