input: Write a python function to create and manipulate a BankAccount object.
  assert bank_operations(["deposit 100", "deposit 50", "withdraw 30", "show_balance"]) == "Your balance is $120.00"
  assert bank_operations(["deposit 200", "withdraw 100", "withdraw 50", "show_balance"]) == "Your balance is $50.00"
  assert bank_operations(["deposit 500", "deposit 200", "withdraw 300", "show_balance"]) == "Your balance is $400.00"
output: def bank_operations(operations):
      class BankAccount:
          def __init__(self):
              self.balance = 0.0
  
          def deposit(self, amount):
              self.balance += amount
  
          def withdraw(self, amount):
              if amount <= self.balance:
                  self.balance -= amount
  
          def show_balance(self):
              return f"Your balance is ${self.balance:.2f}"
  
      account = BankAccount()
      for operation in operations:
          parts = operation.split()
          action = parts[0]
          if action == "deposit":
              account.deposit(float(parts[1]))
          elif action == "withdraw":
              account.withdraw(float(parts[1]))
          elif action == "show_balance":
              return account.show_balance()