212 rollback.py

import sqlite3
import pytz
import datetime

db = sqlite3.connect("accounts.sqlite", detect_types=sqlite3.PARSE_DECLTYPES)
db.execute("CREATE TABLE IF NOT EXISTS accounts (name TEXT PRIMARY KEY NOT NULL, balance INTEGER NOT NULL)")
db.execute("CREATE TABLE IF NOT EXISTS history (time TIMESTAMP NOT NULL, account TEXT NOT NULL, amount"
           " INTEGER NOT NULL, PRIMARY KEY (time, account))")
db.execute("CREATE VIEW IF NOT EXISTS localhistory AS SELECT STRFTIME('%Y-%m-%d %H:%M:%f', "
           "history.time, 'localtime') AS localtime, "
           "history.account, history.amount FROM history ORDER BY history.time")


class Account(object):

    @staticmethod
    def _current_time():
        return pytz.utc.localize(datetime.datetime.utcnow())
        # local_time = pytz.utc.localize(datetime.datetime.utcnow())
        # return local_time.astimezone()

    def __init__(self, name: str, opening_balance: int = 0):
        cursor = db.execute("SELECT name, balance FROM accounts WHERE (name = ?)", (name,))
        row = cursor.fetchone()

        if row:
            self.name, self._balance = row
            print("Record found for: {}".format(self.name), end="")
        else:
            self.name = name
            self._balance = opening_balance
            cursor.execute("INSERT INTO accounts VALUES(?, ?)", (name, opening_balance))
            cursor.connection.commit()
            print("Account created for {}, ".format(self.name), end="")
        self.show_balance()

    def _save_update(self, amount):
        new_balance = self._balance + amount
        deposit_time = Account._current_time()
        db.execute("UPDATE accounts SET balance = ? WHERE (name = ?)", (new_balance, self.name))
        db.execute("INSERT INTO history VALUES(?, ?, ?)", (deposit_time, self.name, amount))
        db.commit()
        self._balance = new_balance

    def deposit(self, amount: int) -> float:
        if amount > 0.0:
            # new_balance = self._balance + amount
            # deposit_time = Account._current_time()
            # db.execute("UPDATE accounts SET balance = ? WHERE (name = ?)", (new_balance, self.name))
            # db.execute("INSERT INTO history VALUES(?, ?, ?)", (deposit_time, self.name, amount))
            # db.commit()
            # self._balance = new_balance
            self._save_update(amount)
            print("{:.2f} deposited".format(amount / 100))
        return self._balance / 100

    def withdraw(self, amount: int) -> float:
        if 0 < amount <= self._balance:
            # new_balance = self._balance - amount
            # withdraw_time = Account._current_time()
            # db.execute("UPDATE accounts SET balance = ? WHERE (name = ?)", (new_balance, self.name))
            # db.execute("INSERT INTO history VALUES (?, ?, ?)", (withdraw_time, self.name, -amount))
            # db.commit()
            # self._balance = new_balance
            self._save_update(-amount)
            print("{:.2f} withdrawn".format(amount / 100))
            return amount / 100
        else:
            print("Amount must be greater than 0 and less than your account balance")
            return 0.0

    def show_balance(self):
        print(" Balance on account {} is {:.2f}".format(self.name, self._balance / 100))


if __name__ == "__main__":
    mario = Account("Mario")
    mario.deposit(1010)
    mario.deposit(1000)
    mario.deposit(10)
    mario.deposit(10)
    mario.withdraw(40)
    mario.withdraw(0)
    mario.show_balance()

    jon = Account("Jon", 1000)
    barry = Account("Barty", 9000)
    eric = Account("Eric", 1000)
    jon.show_balance()
    barry.show_balance()
    eric.show_balance()

    db.close()