expense_tracker.py

import tkinter as tk
from tkinter import messagebox, scrolledtext
import json, os
from datetime import datetime

FILE_NAME = "expenses.json"

# functions 
def initialize_file():
    if not os.path.exists(FILE_NAME):
        with open(FILE_NAME, "w") as f:
            json.dump([], f)

def load_data():
    if not os.path.exists(FILE_NAME):
        return []
    try:
        with open(FILE_NAME, "r") as f:
            return json.load(f)
    except:
        return []

def save_data(expenses):
    with open(FILE_NAME, "w") as f:
        json.dump(expenses, f, indent=2)

def generate_id(expenses):
    return max([e["id"] for e in expenses], default=0) + 1

def validate_amount(a):
    try:
        val = float(a)
        return val if val > 0 else None
    except:
        return None

def validate_date(d):
    try:
        datetime.strptime(d, "%Y-%m-%d")
        return d
    except:
        return None

# Main body
class ExpenseApp:
    def __init__(self, root):
        self.root = root
        self.root.title("Expense Manager")
        self.root.attributes('-fullscreen', True)
        initialize_file()
        self.expenses = load_data()
        self.bg, self.fg, self.ebg = "#1e1e1e", "#ffffff", "#2e2e2e"
        self.root.configure(bg=self.bg)

        # output box
        self.output_area = scrolledtext.ScrolledText(root, width=80, height=25,
                                                     bg=self.ebg, fg=self.fg,
                                                     font=("Consolas", 12))
        self.output_area.pack(pady=10)

        # Buttons
        btn_texts = ["Add Expense", "View Expenses", "Update Expense", 
                     "Delete Expense", "View Summary", "Exit"]
        btn_commands = [self.show_add_form, self.view_expenses, self.show_update_form,
                        self.show_delete_form, self.view_summary, self.root.destroy]

        for t, c in zip(btn_texts, btn_commands):
            tk.Button(root, text=t, width=40, command=c, bg=self.ebg, fg=self.fg).pack(pady=3)

        # Forms 
        self.add_entries = self.create_form(["Amount", "Date (YYYY-MM-DD)", "Note", "Category"], self.submit_add)
        self.update_entries = self.create_form(["Expense ID", "New Amount", "New Date", "New Note", "New Category"], self.submit_update)
        self.delete_entries = self.create_form(["Expense ID"], self.submit_delete)

    # form creation
    def create_form(self, labels, submit_cmd):
        frame = tk.Frame(self.root, bg=self.bg)
        entries = []
        for i, label in enumerate(labels):
            tk.Label(frame, text=label + ":", bg=self.bg, fg=self.fg).grid(row=i, column=0, sticky="e")
            entry = tk.Entry(frame, bg=self.ebg, fg=self.fg, insertbackground=self.fg)
            entry.grid(row=i, column=1)
            entries.append(entry)
        tk.Button(frame, text="Submit", command=submit_cmd, bg=self.ebg, fg=self.fg).grid(row=len(labels), columnspan=2, pady=5)
        return {"frame": frame, "entries": entries}
    # Clear forms 
    def clear_forms(self):
        self.add_entries["frame"].pack_forget()
        self.update_entries["frame"].pack_forget()
        self.delete_entries["frame"].pack_forget()

    # Show forms 
    def show_add_form(self):
        self.clear_forms()
        self.add_entries["frame"].pack(pady=10)
        self.add_entries["entries"][0].focus_set()

    def show_update_form(self):
        self.clear_forms()
        self.update_entries["frame"].pack(pady=10)
        self.update_entries["entries"][0].focus_set()

    def show_delete_form(self):
        self.clear_forms()
        self.delete_entries["frame"].pack(pady=10)
        self.delete_entries["entries"][0].focus_set()

    # CRUD Operations - add
    def submit_add(self):
        amt = validate_amount(self.add_entries["entries"][0].get())
        date = validate_date(self.add_entries["entries"][1].get())
        note = self.add_entries["entries"][2].get()
        cat = self.add_entries["entries"][3].get()
        if amt is None:
            messagebox.showerror("Error", "Invalid amount")
            return
        if date is None:
            messagebox.showerror("Error", "Invalid date format")
            return
        new_id = generate_id(self.expenses)
        self.expenses.append({"id": new_id, "amount": amt, "date": date, "note": note, "category": cat})
        save_data(self.expenses)
        messagebox.showinfo("Success", f"Expense added with ID {new_id}")
        for e in self.add_entries["entries"]:
            e.delete(0, tk.END)
        self.add_entries["frame"].pack_forget()
        self.view_expenses()

    # update
    def submit_update(self):
        try:
            id_ = int(self.update_entries["entries"][0].get())
        except:
            messagebox.showerror("Error", "Invalid ID")
            return
        idx = next((i for i,e in enumerate(self.expenses) if e["id"]==id_), None)
        if idx is None:
            messagebox.showerror("Error", "ID not found")
            return
        changes = {}
        if self.update_entries["entries"][1].get():
            amt = validate_amount(self.update_entries["entries"][1].get())
            if amt is None:
                messagebox.showerror("Error", "Invalid amount")
                return
            changes["amount"] = amt
        if self.update_entries["entries"][2].get():
            date = validate_date(self.update_entries["entries"][2].get())
            if date is None:
                messagebox.showerror("Error", "Invalid date")
                return
            changes["date"] = date
        if self.update_entries["entries"][3].get():
            changes["note"] = self.update_entries["entries"][3].get()
        if self.update_entries["entries"][4].get():
            changes["category"] = self.update_entries["entries"][4].get()
        self.expenses[idx].update(changes)
        save_data(self.expenses)
        messagebox.showinfo("Success", f"Expense ID {id_} updated")
        for e in self.update_entries["entries"]:
            e.delete(0, tk.END)
        self.clear_forms()
        self.view_expenses()

    # delete
    def submit_delete(self):
        try:
            id_ = int(self.delete_entries["entries"][0].get())
        except:
            messagebox.showerror("Error", "Invalid ID")
            return
        idx = next((i for i,e in enumerate(self.expenses) if e["id"]==id_), None)
        if idx is None:
            messagebox.showerror("Error", "ID not found")
            return
        self.expenses.pop(idx)
        save_data(self.expenses)
        messagebox.showinfo("Success", f"Expense ID {id_} deleted")
        self.delete_entries["entries"][0].delete(0, tk.END)
        self.clear_forms()
        self.view_expenses()

    # read,view
    def view_expenses(self):
        if not self.expenses:
            self.output_area.delete(1.0, tk.END)
            self.output_area.insert(tk.END, "No expenses recorded yet.\n")
            return
        text = f"{'ID':<4} {'Date':<10} {'Amount':<10} {'Category':<12} Note\n"
        text += "-"*80 + "\n"
        for e in sorted(self.expenses, key=lambda x: x["date"], reverse=True):
            text += f"{e['id']:<4} {e['date']:<10} {e['amount']:<10.2f} {e.get('category',''):<12} {e.get('note','')}\n"
        self.output_area.delete(1.0, tk.END)
        self.output_area.insert(tk.END, text)

    # summary
    def view_summary(self):
        if not self.expenses:
            self.output_area.delete(1.0, tk.END)
            self.output_area.insert(tk.END, "No expenses recorded yet.\n")
            return
        total, cat_totals = 0, {}
        for e in self.expenses:
            amt = e["amount"]
            cat = e.get("category","Uncategorized") or "Uncategorized"
            total += amt
            cat_totals[cat] = cat_totals.get(cat,0)+amt
        text = "\n====== Expense Summary ======\n"
        for c, amt in cat_totals.items():
            text += f"{c}: ₹{amt:.2f}\n"
        text += "-----------------------------\n"
        text += f"Total Expenses: ₹{total:.2f}\n"
        self.output_area.delete(1.0, tk.END)
        self.output_area.insert(tk.END, text)

# run
if __name__ == "__main__":
    root = tk.Tk()
    app = ExpenseApp(root)
    root.mainloop()