lad 102 done

bank_account.py

@@ -0,0 +1,47 @@
+class BankAccount:
+    def __init__(self, account_holder: str, initial_balance: float = 0):
+        # Validation: holder name
+        if not isinstance(account_holder, str) or not account_holder.strip():
+            raise ValueError("account_holder must be a non-empty string")
+
+        # If initial_balance not provided, default is 0 (already)
+        if not isinstance(initial_balance, (int, float)):
+            raise TypeError("initial_balance must be a number")
+
+        if initial_balance < 0:
+            raise ValueError("initial_balance cannot be negative")
+
+        self._account_holder = account_holder.strip()   # private-ish attribute
+        self._balance = float(initial_balance)
+
+    def deposit(self, amount: float) -> float:
+        # Validation
+        if not isinstance(amount, (int, float)):
+            raise TypeError("deposit amount must be a number")
+
+        if amount <= 0:
+            raise ValueError("deposit amount must be greater than 0")
+
+        self._balance += float(amount)
+        return self._balance
+
+    def withdraw(self, amount: float) -> float:
+        # Validation
+        if not isinstance(amount, (int, float)):
+            raise TypeError("withdraw amount must be a number")
+
+        if amount <= 0:
+            raise ValueError("withdraw amount must be greater than 0")
+
+        # Business rule: must have enough money
+        if amount > self._balance:
+            raise Exception("Insufficient funds")
+
+        self._balance -= float(amount)
+        return self._balance
+
+    def get_balance(self) -> float:
+        return self._balance
+
+    def get_account_holder(self) -> str:
+        return self._account_holder

main.py

@@ -0,0 +1,23 @@
+from bank_account import BankAccount
+
+# Create account
+account = BankAccount("Razan", 100)
+
+print("Account holder:", account.get_account_holder())
+print("Balance:", account.get_balance())
+
+# Deposit
+new_balance = account.deposit(50)
+print("After deposit:", new_balance)
+
+# Withdraw (successful)
+new_balance = account.withdraw(30)
+print("After withdraw:", new_balance)
+
+# Withdraw (insufficient funds) + handle exception
+try:
+    account.withdraw(500)
+except Exception as e:
+    print("Withdraw failed:", e)
+
+print("Final balance:", account.get_balance())