Personal Expense Tracker CLI

import csv
import os
from datetime import datetime

# Define the file name where data will be saved
FILE_NAME = "expenses.csv"

def initialize_file():
  """Creates the CSV file with headers if it doesn't already exist."""
  if not os.path.exists(FILE_NAME):
      with open(FILE_NAME, mode='w', newline='') as file:
          writer = csv.writer(file)
          writer.writerow(["Date", "Category", "Amount", "Description"])

def add_expense():
  """Prompts the user for expense details and saves them to the CSV."""
  print("
--- Add a New Expense ---")
  
  # Get current date automatically
  date_today = datetime.now().strftime("%Y-%m-%d")
  
  category = input("Enter Category (e.g., Food, Transport, Utilities): ").capitalize()
  
  # Error handling to ensure the amount is a valid number
  try:
      amount = float(input("Enter Amount: $"))
  except ValueError:
      print("❌ Invalid input. Please enter a numerical value for the amount.")
      return
      
  description = input("Enter a brief description: ")

  # Append the new record to the CSV file
  with open(FILE_NAME, mode='a', newline='') as file:
      writer = csv.writer(file)
      writer.writerow([date_today, category, amount, description])
  
  print(f"✅ Successfully added: $ {amount:.2f} for {category}.")

def view_summary():
  """Reads the CSV and displays total spending per category."""
  print("
--- Expense Summary ---")
  
  if not os.path.exists(FILE_NAME):
      print("⚠️ No expenses recorded yet.")
      return

  category_totals = {}
  total_spent = 0.0

  # Read the file and calculate totals
  with open(FILE_NAME, mode='r') as file:
      reader = csv.DictReader(file)
      for row in reader:
          category = row["Category"]
          amount = float(row["Amount"])
          
          # Add amount to the specific category
          if category in category_totals:
              category_totals[category] += amount
          else:
              category_totals[category] = amount
              
          total_spent += amount

  # Display the aggregated data
  if total_spent == 0:
      print("No expenses found.")
  else:
      for cat, total in category_totals.items():
          print(f"🔹 {cat}: $ {total:.2f}")
      print("-" * 23)
      print(f"💰 Total Spent: $ {total_spent:.2f}")

def main():
  """The main loop that runs the interactive menu."""
  initialize_file()
  
  while True:
      print("
" + "="*25)
      print("   EXPENSE TRACKER MENU")
      print("="*25)
      print("1. Add an Expense")
      print("2. View Summary")
      print("3. Exit")
      
      choice = input("Select an option (1-3): ")
      
      if choice == '1':
          add_expense()
      elif choice == '2':
          view_summary()
      elif choice == '3':
          print("Exiting Expense Tracker. Have a great day! 👋")
          break
      else:
          print("❌ Invalid choice. Please select 1, 2, or 3.")

if __name__ == "__main__":
  main()