Python Tkinter file dialog

Question

我正在编写一个以tkinter为gui的小型python程序来选择excel文件并打开它们，我达到了可以选择文件并打开它们的地步。我的问题是当用户不选择文件并单击取消它产生和错误时。如果用户没有在tkinter文件对话框中选择文件，如何继续编码？import pandas as pdimport tkinter as tkfrom tkinter import filedialogimport openpyxlfrom openpyxl import load_workbookimport osimport sysimport numpy as nproot = tk.Tk()canvas1 = tk.Canvas(root, width=300, height=300, bg='lightsteelblue')canvas1.pack()def getExcel():    global df    import_file_path = filedialog.askopenfilename()    df = pd.read_excel(import_file_path)    book = load_workbook(import_file_path)    writer = pd.ExcelWriter(import_file_path, engine='openpyxl')    writer.book = book    x3 = (df.loc[(df['Var Cost'] < -500) | (df['Var Cost'] > 500)])    df3 = pd.DataFrame(x3)    df3.to_excel(writer, sheet_name='VarianceSorted')    writer.save()    writer.close()    command = import_file_path    os.system(command)def end():    sys.exit()browseButton_Excel = tk.Button(text='Import Excel File', command=getExcel, bg='green', fg='white', font=('helvetica', 12, 'bold'))canvas1.create_window(150, 150, window=browseButton_Excel)quitbutton = tk.Button(text='Quit', command=end, bg='green', fg='white', font=('helvetica', 12, 'bold'))canvas1.create_window(200, 200, window=quitbutton)root.mainloop()

Answer 1

在继续之前，您应该检查返回的：import_file_path

def getExcel():    global df

    import_file_path = filedialog.askopenfilename()    if import_file_path:
        df = pd.read_excel(import_file_path)
        book = load_workbook(import_file_path)
        writer = pd.ExcelWriter(import_file_path, engine='openpyxl')
        writer.book = book
        x3 = (df.loc[(df['Var Cost'] < -500) | (df['Var Cost'] > 500)])
        df3 = pd.DataFrame(x3)
        df3.to_excel(writer, sheet_name='VarianceSorted')
        writer.save()
        writer.close()
        command = import_file_path
        os.system(command)