Custom Exceptions

class CustomError(Exception):
    pass

# Raising the custom exception
def example_function(x):
    if x < 0:
        raise CustomError("CustomError: Negative value not allowed")

try:
    example_function(-5)
except CustomError as e:
    print(e)

class ValueTooSmallError(Exception):
    def __init__(self, message, value):
        super().__init__(message)
        self.value = value

def example_function(x):
    if x < 0:
        raise ValueTooSmallError(f"ValueTooSmallError: {x} is less than 0", x)

try:
    example_function(-5)
except ValueTooSmallError as e:
    print(f"{e}: The value is {e.value}")

class MyBaseError(Exception):
    """Base class for exceptions in this module."""
    pass

class NetworkError(MyBaseError):
    """Exception raised for network-related errors."""
    def __init__(self, message="Network error occurred"):
        self.message = message
        super().__init__(self.message)

class DatabaseError(MyBaseError):
    """Exception raised for database-related errors."""
    def __init__(self, message="Database error occurred"):
        self.message = message
        super().__init__(self.message)

# Raising different custom exceptions
def network_operation():
    raise NetworkError()

def database_operation():
    raise DatabaseError()

try:
    network_operation()
except NetworkError as e:
    print(e)
except DatabaseError as e:
    print(e)

class InsufficientFundsError(Exception):
    def __init__(self, balance, amount):
        super().__init__(f"Insufficient funds: Cannot withdraw {amount}, balance is {balance}")
        self.balance = balance
        self.amount = amount

class BankAccount:
    def __init__(self, balance):
        self.balance = balance

    def withdraw(self, amount):
        if amount > self.balance:
            raise InsufficientFundsError(self.balance, amount)
        self.balance -= amount
        return self.balance

# Testing the custom exception in a banking scenario
account = BankAccount(100)

try:
    account.withdraw(150)
except InsufficientFundsError as e:
    print(e)