johanbeytell1 · Oct 30, 2026 · Oct 30, 2026
diff --git a/Beginner/14_address_book.py b/Beginner/14_address_book.py
@@ -1,42 +1,107 @@
 import json
 import os
+import re
 
 CONTACTS_FILE = "contacts.json"
 
+# Matches names that already end in a numbered suffix, e.g. "Rani (2)".
+NUMBERED_NAME = re.compile(r"^(.*?)\s*\((\d+)\)$")
+
+
 def load_contacts():
     if os.path.exists(CONTACTS_FILE):
         with open(CONTACTS_FILE, "r") as f:
             return json.load(f)
     return {}
 
+
 def save_contacts(contacts):
     with open(CONTACTS_FILE, "w") as f:
         json.dump(contacts, f, indent=4)
 
+
+def next_available_name(contacts, name):
+    """Return the first free numbered name, e.g. 'Rani (2)', 'Rani (3)', ..."""
+    base = name
+    index = 2
+
+    match = NUMBERED_NAME.match(name)
+    if match:
+        base = match.group(1)
+        index = max(2, int(match.group(2)) + 1)
+
+    while f"{base} ({index})" in contacts:
+        index += 1
+    return f"{base} ({index})"
+
+
+def resolve_name(contacts, name):
+    """Handle duplicate names without silently overwriting a contact.
+
+    Returns the name to save the new contact under, or None if the user
+    cancels. Existing contacts are only replaced after explicit confirmation.
+    """
+    if name not in contacts:
+        return name
+
+    existing = contacts[name]
+    print(f"A contact named '{name}' already exists.")
+    print(f"  Phone: {existing['phone']}, Email: {existing['email']}")
+    suggested = next_available_name(contacts, name)
+
+    while True:
+        print("What would you like to do?")
+        print("1. Overwrite the existing contact")
+        print(f"2. Keep both (save the new contact as '{suggested}')")
+        print("3. Cancel")
+        choice = input("Enter your choice: ")
+
+        if choice == "1":
+            return name
+        elif choice == "2":
+            return suggested
+        elif choice == "3":
+            return None
+        else:
+            print("Invalid choice. Please try again.")
+
+
 def add_contact(contacts):
-    name = input("Enter name: ")
+    name = input("Enter name: ").strip()
+    if not name:
+        print("Name cannot be empty.")
+        return
+
+    name = resolve_name(contacts, name)
+    if name is None:
+        print("Contact not added.")
+        return
+
     phone = input("Enter phone number: ")
     email = input("Enter email address: ")
     contacts[name] = {"phone": phone, "email": email}
     save_contacts(contacts)
     print(f"Contact '{name}' added.")
 
+
 def view_contacts(contacts):
     if not contacts:
         print("No contacts found.")
         return
     for name, info in contacts.items():
         print(f"Name: {name}, Phone: {info['phone']}, Email: {info['email']}")
 
+
 def delete_contact(contacts):
-    name = input("Enter the name of the contact to delete: ")
+    name = input("Enter the name of the contact to delete: ").strip()
     if name in contacts:
         del contacts[name]
         save_contacts(contacts)
         print(f"Contact '{name}' deleted.")
     else:
         print("Contact not found.")
 
+
 def main():
     contacts = load_contacts()
     while True:
@@ -58,5 +123,6 @@ def main():
         else:
             print("Invalid choice. Please try again.")
 
+
 if __name__ == "__main__":
     main()
diff --git a/README.md b/README.md
@@ -28,6 +28,7 @@ This repository is designed to help Python learners at all levels, starting with
 - Temperature Converter validates the input against absolute zero for **each unit** (−273.15°C or −459.67°F) and reports invalid values.
 - Roman Numeral Converter rejects noncanonical numerals (such as `IIII` and `IC`) and values outside 1–3999.
 - JSON Reader now uses a Python 3.6-compatible type annotation instead of Python 3.10's `|` union syntax.
+- Address Book no longer silently overwrites contacts that share a name. It now asks whether to overwrite, keep both (saving the new contact as `Name (2)`, `Name (3)`, …), or cancel.
 
 </details>
 
@@ -592,6 +593,7 @@ These projects are ideal for those new to Python. Each project includes a descri
   1. Create functions to add, view, and delete contacts.
   2. Store contacts in a file (e.g., JSON).
   3. Create a main loop to interact with the user.
+  4. Check for an existing contact with the same name before saving.
 - **Tips:**
 
     <details><summary>Tip 1:</summary>
@@ -604,6 +606,13 @@ These projects are ideal for those new to Python. Each project includes a descri
   Use the `json` module to save and load contacts from a file.
 
     </details>
+    <details><summary>Tip 3:</summary>
+
+  Never overwrite a contact silently. Check whether the name already exists and ask the user what to do: overwrite it, cancel, or keep both by saving the new contact under an incremented name like `Rani (2)`, `Rani (3)`, and so on.
+
+  Thanks to [@SVarnavi06](https://github.com/SVarnavi06) for pointing out the silent overwrite bug in [issue #18](https://github.com/Infinitode/Python-Projects/issues/18)!
+
+    </details>
 
 ### 15. Pomodoro Timer