fix value nan/add view

upload.py

@@ -0,0 +1,17 @@
+import pandas as pd
+import mysql.connector
+import math
+import xlsxwriter
+import tkinter as tk
+from tkinter import filedialog,messagebox
+from datetime import datetime
+from mysql.connector import Error
+
+def upload_excel():
+    # Crea una finestra di dialogo per selezionare il file
+    root = tk.Tk()
+    root.withdraw()  # Nasconde la finestra principale
+    file_path = filedialog.askopenfilename(title="Seleziona un file Excel", 
+                                            filetypes=[("Tutti i file","*.*")])
+    excel_filename = r"{}".format(file_path)
+    return excel_filename