Project: CSV Contact Manager0%
Creating Classes & Objects (Review)

Project: CSV Contact Manager

Beginner12 min read•Updated: Jul 11, 2026
Study Materials

Project: CSV Contact Manager

In this hands-on project, we will apply the advanced file handling techniques covered in this chapter—including csv.DictReader, csv.DictWriter, context managers, and robust error handling—to build a persistent Command-Line CSV Contact Manager.

1. Project Specifications & Requirements

The application will manage contact records and save them to contacts.csv. Key capabilities:

  1. 1
    Data Persistence: Automatically reads from and writes to a structured CSV file.
  2. 2
    Auto-Initialization: Gracefully initializes the CSV file with headers if it does not yet exist.
  3. 3
    Core CRUD Operations:
  • Create: Add new contacts with validation.
  • Read: Display all contacts in a formatted table.
  • Search: Case-insensitive search by name or category.
  • Delete: Remove a contact by name and rewrite the updated dataset.
  1. 1
    Safety: Handles missing files, invalid inputs, and file permissions without crashing.

2. Complete Application Code

Python
import csv
import os
 
CSV_FILE = "contacts.csv"
FIELDNAMES = ["name", "phone", "email", "category"]
 
 
def initialize_storage():
"""Ensures the CSV file exists with the proper column headers."""
if not os.path.exists(CSV_FILE):
try:
with open(CSV_FILE, mode="w", encoding="utf-8", newline="") as f:
writer = csv.DictWriter(f, fieldnames=FIELDNAMES)
writer.writeheader()
except OSError as err:
print(f"Error initializing contact database: {err}")
 
 
def load_contacts():
"""Loads and returns all contacts as a list of dictionaries."""
contacts = []
try:
with open(CSV_FILE, mode="r", encoding="utf-8", newline="") as f:
reader = csv.DictReader(f)
for row in reader:
contacts.append(row)
except FileNotFoundError:
initialize_storage()
except OSError as err:
print(f"Error reading {CSV_FILE}: {err}")
return contacts
 
 
def save_contacts(contacts):
"""Overwrites the CSV file with the provided list of contact dictionaries."""
try:
with open(CSV_FILE, mode="w", encoding="utf-8", newline="") as f:
writer = csv.DictWriter(f, fieldnames=FIELDNAMES)
writer.writeheader()
writer.writerows(contacts)
return True
except OSError as err:
print(f"Failed to save contacts: {err}")
return False
 
 
def add_contact():
"""Prompts for contact details and appends to CSV."""
print("\n--- Add New Contact ---")
name = input("Enter Full Name: ").strip()
phone = input("Enter Phone Number: ").strip()
email = input("Enter Email Address: ").strip()
category = input("Enter Category (Family/Work/Friend): ").strip().capitalize()
 
if not name or not phone:
print("Error: Name and Phone number are required fields!")
return
 
contacts = load_contacts()
# Check for duplicate names
if any(c["name"].lower() == name.lower() for c in contacts):
print(f"A contact named '{name}' already exists.")
return
 
new_contact = {
"name": name,
"phone": phone,
"email": email or "N/A",
"category": category or "General"
}
 
contacts.append(new_contact)
if save_contacts(contacts):
print(f"Contact '{name}' added successfully!")
 
 
def view_contacts():
"""Displays all contacts in a formatted table."""
contacts = load_contacts()
if not contacts:
print("\nNo contacts found. Add one first!")
return
 
print("\n" + "=" * 65)
print(f"{'NAME':<20} | {'PHONE':<15} | {'CATEGORY':<10} | {'EMAIL'}")
print("-" * 65)
for c in contacts:
print(f"{c['name']:<20} | {c['phone']:<15} | {c['category']:<10} | {c['email']}")
print("=" * 65)
 
 
def search_contact():
"""Searches contacts by name or category substring."""
query = input("\nEnter search term (name or category): ").strip().lower()
contacts = load_contacts()
results = [
c for c in contacts
if query in c["name"].lower() or query in c["category"].lower()
]
 
if not results:
print(f"No contacts matching '{query}'.")
return
 
print(f"\nFound {len(results)} match(es):")
for c in results:
print(f" - {c['name']} ({c['category']}): {c['phone']} | {c['email']}")
 
 
def delete_contact():
"""Deletes a contact by exact name."""
name_to_delete = input("\nEnter exact name of contact to delete: ").strip().lower()
contacts = load_contacts()
initial_count = len(contacts)
updated_contacts = [c for c in contacts if c["name"].lower() != name_to_delete]
 
if len(updated_contacts) == initial_count:
print(f"No contact found with name '{name_to_delete}'.")
else:
if save_contacts(updated_contacts):
print("Contact deleted successfully.")
 
 
def main_menu():
"""Main user interaction loop."""
initialize_storage()
while True:
print("\n===== CONTACT MANAGER (CSV) =====")
print("1. View All Contacts")
print("2. Add New Contact")
print("3. Search Contact")
print("4. Delete Contact")
print("5. Exit")
 
choice = input("Select an option (1-5): ").strip()
 
if choice == "1":
view_contacts()
elif choice == "2":
add_contact()
elif choice == "3":
search_contact()
elif choice == "4":
delete_contact()
elif choice == "5":
print("Exiting Contact Manager. Goodbye!")
break
else:
print("Invalid choice. Please choose between 1 and 5.")
 
 
if __name__ == "__main__":
main_menu()

3. Sample Execution Output

Output
===== CONTACT MANAGER (CSV) =====
1. View All Contacts
2. Add New Contact
3. Search Contact
4. Delete Contact
5. Exit
Select an option (1-5): 2
 
--- Add New Contact ---
Enter Full Name: Anita Desai
Enter Phone Number: +91-9876543210
Enter Email Address: anita@example.com
Enter Category (Family/Work/Friend): Work
Contact 'Anita Desai' added successfully!
 
===== CONTACT MANAGER (CSV) =====
1. View All Contacts
2. Add New Contact
3. Search Contact
4. Delete Contact
5. Exit
Select an option (1-5): 1
 
=================================================================
NAME | PHONE | CATEGORY | EMAIL
-----------------------------------------------------------------
Anita Desai | +91-9876543210 | Work | anita@example.com
=================================================================

Multiple Choice Questions

1. In our Contact Manager, what happens if contacts.csv does not exist when the program boots?

A. The script crashes immediately with a FileNotFoundError B. initialize_storage() creates the file and writes the header row using csv.DictWriter C. Python waits for user input before attempting any file access D. An in-memory SQLite database is used instead Answer: B Explanation: initialize_storage() checks if the file exists; if not, it opens the file with mode 'w' and calls writer.writeheader() to establish the schema.

2. How does the delete_contact() function remove a record from the CSV file?

A. By seeking directly to the byte offset in the CSV file and issuing f.truncate() B. By loading records into memory, filtering out the deleted entry, and rewriting the entire file C. By writing an empty dictionary at the row index D. The csv module does not support deleting records Answer: B Explanation: In standard sequential text/CSV files, deleting a record requires filtering the in-memory list of records and rewriting the updated collection with save_contacts().

3. Why is newline='' supplied to open() during both load and save operations?

A. To convert single quotes to double quotes automatically B. To ensure consistent line termination across Windows, Linux, and macOS without extra blank lines C. To prevent Unicode characters from being parsed D. To disable buffering for faster disk writes Answer: B Explanation: The newline='' argument ensures Python's file object delegates all newline translation to the CSV reader/writer, preventing unwanted blank lines on Windows platforms.

4. Which method of csv.DictWriter writes all dictionary rows in a single step?

A. writer.dump_all() B. writer.write_batch() C. writer.writerows() D. writer.save() Answer: C Explanation: writer.writerows(iterable_of_dicts) accepts an iterable of row dictionaries and writes them all into the CSV file.

5. Why is csv.DictReader preferred over index-based csv.reader for storing entities with multiple attributes like contacts?

A. DictReader is written in C and runs 10x faster B. Attributes can be accessed safely by column name (e.g. c['phone']), making the code resilient to column reordering C. DictReader encrypts user passwords automatically D. DictReader handles binary image files Answer: B Explanation: DictReader accesses values by header names instead of fixed integer indices, preventing bugs when columns are added, removed, or reordered in the CSV file.

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