03-building-expenses-tracker.py

"""
This is a simple expense tracker program that allows users to add, list, and filter expenses by category.
It uses a list of dictionaries to store the expenses, where each dictionary contains the amount and category of the expense.
The program provides functions to add expenses, print all expenses, calculate total expenses, and filter expenses by category.
The user can interact with the program through a simple command-line interface.
It allows users to add expenses, view all expenses, calculate total expenses, and filter expenses by category.
"""

def add_expense(expenses, amount, category):
    expenses.append({'amount': amount, 'category': category})
    
def print_expenses(expenses):
    for expense in expenses:
        print(f'Amount: {expense["amount"]}, Category: {expense["category"]}')
    
def total_expenses(expenses):
    return sum(map(lambda expense: expense['amount'], expenses))
    
def filter_expenses_by_category(expenses, category):
    return filter(lambda expense: expense['category'] == category, expenses)

    

def main():
    expenses = []
    while True:
        print('\nExpense Tracker')
        print('1. Add an expense')
        print('2. List all expenses')
        print('3. Show total expenses')
        print('4. Filter expenses by category')
        print('5. Exit')
       
        choice = input('Enter your choice: ')

        if choice == '1':
            amount = float(input('Enter amount: '))
            category = input('Enter category: ')
            add_expense(expenses, amount, category)

        elif choice == '2':
            print('\nAll Expenses:')
            print_expenses(expenses)
    
        elif choice == '3':
            print('\nTotal Expenses: ', total_expenses(expenses))
    
        elif choice == '4':
            category = input('Enter category to filter: ')
            print(f'\nExpenses for {category}:')
            expenses_from_category = filter_expenses_by_category(expenses, category)
            print_expenses(expenses_from_category)
    
        elif choice == '5':
            print('Exiting the program.')
            break




if __name__ == '__main__':
    main()