Added a Simple Banking App

Banking App/Readme.md

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+## A Banking App
+
+
+A simple python program that uses luhn algorithm to verify card number, enables transfer and withdrawal of money It makes use of sqlite3 for database storage and therefore permits manipulation of our details and keeps them safe.

Banking App/banking.py

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+
+import random
+import sys
+import sqlite3
+random.seed()
+
+
+conn = sqlite3.connect('card.s3db')
+cur = conn.cursor()
+# cur.execute("DROP TABLE card")
+cur.execute("CREATE TABLE IF NOT EXISTS card(id INTEGER PRIMARY KEY,number TEXT,pin TEXT,balance INTEGER DEFAULT 0);")
+conn.commit()
+
+
+class Card:
+
+    def __init__(self):
+        self.card = ''
+        self.pin = ''
+        self.login_card = ''
+        self.login_pin = ''
+        self.row = []
+        self.balance = 0
+        self.receiver_balance = 0
+
+    def create_account(self):
+        print("Your card has been created")
+        print("Your card number:")
+        self.card = '400000' + str(random.randint(100000000, 999999999)) 
+        print(self.luhn())
+        print("Your card PIN:")
+        self.pin = str(random.randint(1000, 9999))
+        print(self.pin)
+        cur.execute(f"""INSERT INTO card (number, pin) VALUES ({self.card}, {self.pin});""")
+        conn.commit()
+
+    def log_in(self):
+
+        self.login_card = input("Enter your card number:\n")
+        self.login_pin = input("Enter your PIN:\n")
+
+        cur.execute(f"""SELECT
+                            id,
+                            number,
+                            pin,
+                            balance
+                        FROM 
+                            card
+                        WHERE
+                            number = {self.login_card}
+                            AND pin = {self.login_pin}
+                        ;""")
+
+        self.row = cur.fetchone()
+        if self.row:
+            self.balance = self.row[3]
+            print('\nYou have successfully logged in')
+            self.success()
+
+        else:
+            print("wrong card number or pin")
+
+        '''elif not self.luhn_2(self.login_card):
+            print('Probably you made a mistake in the card number. Please try again!')'''
+
+    def success(self):
+        while True:
+            print("""\n1. Balance
+2. Add income
+3. Do transfer
+4. Close account
+5. Log out
+0. Exit""")
+            i = int(input())
+            if i == 1:
+                print('\nBalance: ', self.balance)
+                print()
+            elif i == 2:
+                print('\nEnter income:')
+                amount = int(input())
+                self.balance += amount
+                cur.execute(f'UPDATE card SET balance = {self.balance} WHERE number = {self.login_card};')
+                conn.commit()
+                print('Income was added!')
+            elif i == 3:
+                print('\nTransfer\nEnter card number:')
+                receiver_card = input()
+                cur.execute(f'SELECT id, number,pin,balance FROM card WHERE number = {receiver_card};')
+
+                if not self.luhn_2(receiver_card):
+                    print('Probably you made a mistake in the card number. Please try again!')
+                elif not cur.fetchone():
+                    print('Such a card does not exist.')
+                else:
+                    transfer = int(input("Enter how much money you want to transfer:\n"))
+                    if transfer > self.balance:
+                        print("Not enough money!")
+                    else:
+                        self.balance -= transfer
+                        cur.execute(f'UPDATE card SET balance = {self.balance} WHERE number = {self.login_card};')
+                        self.receiver_balance += transfer
+                        cur.execute(f'UPDATE card SET balance = {self.receiver_balance} WHERE number = {receiver_card};')
+                        cur.execute(f'SELECT * FROM card WHERE number = {self.login_card}')
+                        print(cur.fetchone())
+                        print("Success!")
+                        conn.commit()
+
+            elif i == 4:
+                cur.execute(f"DELETE FROM card WHERE number = {self.login_card}")
+                conn.commit()
+                print('\nThe account has been closed!')
+                break
+            elif i == 5:
+                print("\nYou have successfully log out!")
+                break
+            elif i == 0:
+                print("\nBye!")
+                conn.close()
+                sys.exit()
+
+    def luhn_2(self, num):
+        num2 = num[:]
+        num2 = num2[::-1]
+        lst = [int(x) for x in num2]
+        s1 = sum(lst[::2])
+        for i in range(len(lst)):
+            if i % 2 != 0:
+                lst[i] = lst[i] * 2
+        for i in range(len(lst)):
+            if lst[i] > 9:
+                lst[i] -= 9
+        s2 = sum(lst[1:len(lst):2])
+
+        if (s1 + s2) % 10 == 0:
+            return True
+        return False
+
+    # Defining my luhn algorithm for creating a new card number
+    def luhn(self):
+
+        lst2 = [int(x) for x in self.card]
+        lst3 = lst2[:]
+
+        for i in range(len(lst3)):
+            if i % 2 == 0:
+                lst3[i] = lst3[i] * 2
+            else:
+                lst3[i] = lst3[i]
+
+        for i in range(len(lst3)):
+            if lst3[i] > 9:
+                lst3[i] -= 9
+
+        tot = sum(lst3)
+        count_sum = 0
+        while True:
+            if (tot + count_sum) % 10 == 0:
+                break
+            else:
+                count_sum += 1
+
+        lst2.append(count_sum)
+        self.card = (''.join(map(str, lst2)))
+
+        return self.card
+
+    def menu(self):
+        while True:
+            print("""\n1. Create an account
+2. Log into account
+0. Exit""")
+            i = int(input())
+            if i == 1:
+                self.create_account()
+            elif i == 2:
+                self.log_in()
+            elif i == 0:
+                conn.close()
+                print("\nBye!")
+                break
+            else:
+                print("Invalid input")
+
+
+card = Card()
+card.menu()