csv2excel.py

import os
import pandas as pd
import tkinter as tk
from tkinter import filedialog, messagebox
from openpyxl import Workbook
from openpyxl.styles import Font, PatternFill, Alignment, Border, Side
from openpyxl.utils import get_column_letter


class ConverterApp:
    def __init__(self, root):
        self.root = root
        self.root.title("CSV to Excel Converter")
        self.root.geometry("440x280")
        self.root.resizable(False, False)

        self.file_path = None
        self.df = None

        # Upload button
        tk.Button(
            root,
            text="Upload CSV",
            width=30,
            command=self.upload_file
        ).pack(pady=15)

        # Selected file label
        self.file_label = tk.Label(
            root,
            text="No file selected",
            fg="gray"
        )
        self.file_label.pack()

        # Convert button
        self.convert_btn = tk.Button(
            root,
            text="Convert to Excel",
            width=30,
            state=tk.DISABLED,
            command=self.convert_file
        )
        self.convert_btn.pack(pady=25)

    def upload_file(self):
        self.file_path = filedialog.askopenfilename(
            title="Select CSV file",
            filetypes=[
                ("CSV files", "*.csv"),
            ]
        )

        if not self.file_path:
            return

        self.file_label.config(
            text=os.path.basename(self.file_path),
            fg="black"
        )

        try:
            self.df = pd.read_csv(self.file_path, dtype=str)

            # ---- AUTO ADD No COLUMN IF MISSING ----
            if "No" not in self.df.columns and "No." not in self.df.columns:
                self.df.insert(0, "No", range(1, len(self.df) + 1))

            # ---- amount: FORCE 2 DECIMAL PLACES + THOUSANDS ----
            if "amount" in self.df.columns:
                self.df["amount"] = (
                    self.df["amount"]
                    .astype(str)
                    .str.replace(",", "", regex=False)
                    .apply(lambda x: f"{float(x):,.2f}" if x not in ("nan", "", "None") else "0.00")
                )

            self.convert_btn.config(state=tk.NORMAL)

        except Exception as e:
            messagebox.showerror("Error", str(e))

    def convert_file(self):
        save_path = filedialog.asksaveasfilename(
            title="Save Excel file",
            defaultextension=".xlsx",
            filetypes=[("Excel files", "*.xlsx")]
        )

        if not save_path:
            return

        try:
            wb = Workbook()
            ws = wb.active
            ws.title = "Data"

            # ---- STYLES ----
            header_font = Font(name="Calibri", bold=True, color="FFFFFF", size=11)
            header_fill = PatternFill(fill_type="solid", fgColor="2F75B6")
            header_align = Alignment(horizontal="center", vertical="center", wrap_text=True)

            data_font = Font(name="Calibri", size=11)
            data_align_center = Alignment(horizontal="center", vertical="center")
            data_align_right = Alignment(horizontal="right", vertical="center")

            alt_fill = PatternFill(fill_type="solid", fgColor="DDEBF7")

            thin = Side(style="thin", color="BFBFBF")
            border = Border(left=thin, right=thin, top=thin, bottom=thin)

            # ---- HEADER ROW ----
            headers = list(self.df.columns)
            for col_idx, col_name in enumerate(headers, start=1):
                cell = ws.cell(row=1, column=col_idx, value=col_name)
                cell.font = header_font
                cell.fill = header_fill
                cell.alignment = header_align
                cell.border = border

            # ---- DATA ROWS ----
            amount_col = headers.index("amount") + 1 if "amount" in headers else None

            for row_idx, row in enumerate(self.df.itertuples(index=False), start=2):
                fill = alt_fill if row_idx % 2 == 0 else None
                for col_idx, value in enumerate(row, start=1):
                    cell = ws.cell(row=row_idx, column=col_idx, value=value)
                    cell.font = data_font
                    cell.border = border
                    if col_idx == amount_col:
                        cell.alignment = data_align_right
                    else:
                        cell.alignment = data_align_center
                    if fill:
                        cell.fill = fill

            # ---- COLUMN WIDTHS ----
            for col_idx, col_name in enumerate(headers, start=1):
                values = [len(str(v)) for v in self.df.iloc[:, col_idx - 1]]
                max_len = max([len(str(col_name))] + values) if values else len(str(col_name))
                ws.column_dimensions[get_column_letter(col_idx)].width = min(max_len + 4, 40)

            # ---- FREEZE HEADER ----
            ws.freeze_panes = "A2"

            wb.save(save_path)

            messagebox.showinfo(
                "Success",
                "File converted successfully!"
            )

        except Exception as e:
            messagebox.showerror("Error", str(e))


if __name__ == "__main__":
    root = tk.Tk()
    app = ConverterApp(root)
    root.mainloop()