import random

import time
import datetime

# Simulate user accounts

accounts = {
"1234567890": {"balance": 1000, "name": "Alice", "pin": "1234", "transactions": []},
"9876543210": {"balance": 500, "name": "Bob", "pin": "5678", "transactions": []},
}

def generate_otp():
"""Generates a 6-digit OTP."""
return str(random.randint(100000, 999999))

def send_otp(account_number, otp):

"""Simulates sending an OTP."""
print(f"Sending OTP {otp} to account {account_number}...")
time.sleep(1)
print("OTP sent.")
return otp

def verify_otp(sent_otp):
"""Verifies the OTP."""
user_otp = input("Enter the OTP you received: ")
return user_otp == sent_otp

def record_transaction(account_number, transaction_type, amount, success):

"""Records a transaction."""
timestamp = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
transaction = {"type": transaction_type, "amount": amount, "timestamp": timestamp,
"success": success}
accounts[account_number]["transactions"].append(transaction)

def withdraw(account_number, amount):

"""Handles withdrawal."""
if amount <= 0:
print("Invalid withdrawal amount.")
return

if amount > accounts[account_number]["balance"]:

print("Insufficient funds.")
record_transaction(account_number, "withdrawal", amount, False)
return
 otp = generate_otp()
sent_otp = send_otp(account_number, otp)

if verify_otp(sent_otp):
accounts[account_number]["balance"] -= amount
print(f"Withdrawal of ${amount} successful.")
print(f"New balance: ${accounts[account_number]['balance']}")
record_transaction(account_number, "withdrawal", amount, True)
else:
print("Incorrect OTP. Transaction cancelled.")
record_transaction(account_number, "withdrawal", amount, False)

def check_balance(account_number):
"""Checks balance."""
print(f"Your current balance is: ${accounts[account_number]['balance']}")

def view_transaction_history(account_number):
"""Views transaction history."""
print("\nTransaction History:")
if not accounts[account_number]["transactions"]:
print("No transactions recorded yet.")
return

for transaction in accounts[account_number]["transactions"]:

print(f"Type: {transaction['type']}, Amount: ${transaction['amount']}, Timestamp:
{transaction['timestamp']}, Success: {'Yes' if transaction['success'] else 'No'}")

def change_pin(account_number):
"""Changes PIN."""
for attempt in range(3):
current_pin = input("Enter your current PIN: ")
if current_pin == accounts[account_number]["pin"]:
while True:
new_pin = input("Enter your new 4-digit PIN: ")
if new_pin.isdigit() and len(new_pin) == 4:
confirm_new_pin = input("Confirm your new PIN: ")
if new_pin == confirm_new_pin:
accounts[account_number]["pin"] = new_pin
print("PIN changed successfully.")
return True
else:
print("New PINs do not match. Please try again.")
else:
print("Invalid PIN. Please enter a 4-digit number.")
 break
else:
print(f"Incorrect PIN. Attempts remaining: {2 - attempt}")
print("Too many incorrect PIN attempts. PIN change failed.")
return False

def get_account_number():
"""Gets and validates account number."""
while True:
account_number = input("Enter your account number: ")
if account_number.isdigit() and len(account_number) == 10:
return account_number
else:
print("Invalid account number. Please enter a 10 digit number")

def get_pin(account_number):
"""Gets and verifies PIN."""
for attempt in range(3):
pin = input("Enter your 4-digit PIN: ")
if pin == accounts[account_number]["pin"]:
return True
else:
print(f"Incorrect PIN. Attempts remaining: {2 - attempt}")
print("Too many incorrect PIN attempts. Account locked.")
return False

def get_amount():
"""Gets and validates amount."""
while True:
try:
amount = float(input("Enter the amount: $"))
if amount > 0:
return amount
else:
print("Please enter a positive amount")
except ValueError:
print("Invalid input. Please enter a number.")

if __name__ == "__main__":
print("Welcome to the Bank Transaction System")
account_number = get_account_number()

if account_number not in accounts:

print("Account not found.")
 elif get_pin(account_number):
while True:
print("\nChoose an action:")
print("1. Withdraw")
print("2. Check Balance")
print("3. View Transaction History")
print("4. Change PIN")
print("5. Exit")

choice = input("> ")

if choice == "1":
amount = get_amount()
withdraw(account_number, amount)
elif choice == "2":
check_balance(account_number)
elif choice == "3":
view_transaction_history(account_number)
elif choice == "4":
change_pin(account_number)
elif choice == "5":
break
else:
print("Invalid choice.")
else:import random
import time
import datetime

# Simulate user accounts

accounts = {
"1234567890": {"balance": 1000, "name": "Alice", "pin": "1234", "transactions": []},
"9876543210": {"balance": 500, "name": "Bob", "pin": "5678", "transactions": []},
}

def generate_otp():
"""Generates a 6-digit OTP."""
return str(random.randint(100000, 999999))

def send_otp(account_number, otp):

"""Simulates sending an OTP."""
print(f"Sending OTP {otp} to account {account_number}...")
time.sleep(1)
print("OTP sent.")
return otp
def verify_otp(sent_otp):
"""Verifies the OTP."""
user_otp = input("Enter the OTP you received: ")
return user_otp == sent_otp

def record_transaction(account_number, transaction_type, amount, success):

"""Records a transaction."""
timestamp = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
transaction = {"type": transaction_type, "amount": amount, "timestamp": timestamp,
"success": success}
accounts[account_number]["transactions"].append(transaction)

def withdraw(account_number, amount):

"""Handles withdrawal."""
if amount <= 0:
print("Invalid withdrawal amount.")
return

if amount > accounts[account_number]["balance"]:

print("Insufficient funds.")
record_transaction(account_number, "withdrawal", amount, False)
return

otp = generate_otp()
sent_otp = send_otp(account_number, otp)

if verify_otp(sent_otp):
accounts[account_number]["balance"] -= amount
print(f"Withdrawal of ${amount} successful.")
print(f"New balance: ${accounts[account_number]['balance']}")
record_transaction(account_number, "withdrawal", amount, True)
else:
print("Incorrect OTP. Transaction cancelled.")
record_transaction(account_number, "withdrawal", amount, False)

def check_balance(account_number):
"""Checks balance."""
print(f"Your current balance is: ${accounts[account_number]['balance']}")

def view_transaction_history(account_number):
"""Views transaction history."""
print("\nTransaction History:")
if not accounts[account_number]["transactions"]:
 print("No transactions recorded yet.")
return

for transaction in accounts[account_number]["transactions"]:

print(f"Type: {transaction['type']}, Amount: ${transaction['amount']}, Timestamp:
{transaction['timestamp']}, Success: {'Yes' if transaction['success'] else 'No'}")

def change_pin(account_number):
"""Changes PIN."""
for attempt in range(3):
current_pin = input("Enter your current PIN: ")
if current_pin == accounts[account_number]["pin"]:
while True:
new_pin = input("Enter your new 4-digit PIN: ")
if new_pin.isdigit() and len(new_pin) == 4:
confirm_new_pin = input("Confirm your new PIN: ")
if new_pin == confirm_new_pin:
accounts[account_number]["pin"] = new_pin
print("PIN changed successfully.")
return True
else:
print("New PINs do not match. Please try again.")
else:
print("Invalid PIN. Please enter a 4-digit number.")
break
else:
print(f"Incorrect PIN. Attempts remaining: {2 - attempt}")
print("Too many incorrect PIN attempts. PIN change failed.")
return False

def get_account_number():
"""Gets and validates account number."""
while True:
account_number = input("Enter your account number: ")
if account_number.isdigit() and len(account_number) == 10:
return account_number
else:
print("Invalid account number. Please enter a 10 digit number")

def get_pin(account_number):
"""Gets and verifies PIN."""
for attempt in range(3):
pin = input("Enter your 4-digit PIN: ")
if pin == accounts[account_number]["pin"]:
 return True
else:
print(f"Incorrect PIN. Attempts remaining: {2 - attempt}")
print("Too many incorrect PIN attempts. Account locked.")
return False

def get_amount():
"""Gets and validates amount."""
while True:
try:
amount = float(input("Enter the amount: $"))
if amount > 0:
return amount
else:
print("Please enter a positive amount")
except ValueError:
print("Invalid input. Please enter a number.")

if __name__ == "__main__":
print("Welcome to the Bank Transaction System")
account_number = get_account_number()

if account_number not in accounts:

print("Account not found.")
elif get_pin(account_number):
while True:
print("\nChoose an action:")
print("1. Withdraw")
print("2. Check Balance")
print("3. View Transaction History")
print("4. Change PIN")
print("5. Exit")

choice = input("> ")

if choice == "1":
amount = get_amount()
withdraw(account_number, amount)
elif choice == "2":
check_balance(account_number)
elif choice == "3":
view_transaction_history(account_number)
elif choice == "4":
change_pin(account_number)
 elif choice == "5":
break
else:
print("Invalid choice.")
else:
print("Login Failed.")
print("Login Failed.")