小编Abb*_*lla的帖子

错误: names = curfetchone()[0]

TypeError: 'NoneType' object is not subscriptable. 

我试过检查缩进但仍然有错误.我读到如果数据库中没有文件名记录,那么变量名称可能会返回'None'.

我在其他'def'中使用相同的变量'names',它工作正常.我确定它与返回的'None'值有关.

global filename
global t
try:
    con = sqlite3.connect('textdb.db')
    cur = con.cursor()

    filename = tkinter.simpledialog.askstring("Open file...", "Input filename to open:")

    if filename != None:
        cur.execute("SELECT file_name FROM file_info WHERE file_name = ?", (filename,))
        names = cur.fetchone()[0]
        same = str(names)
        if filename == same:
            cur.execute("SELECT file_content FROM file_info WHERE file_name = ?", (filename,))
            content = cur.fetchone()[0]
            t = str(content)
            text.delete(0.0, END)
            text.insert(0.0, t)
        else:
            result = tkinter.messagebox.askyesno(title="File doesn't exist", message="'"+(filename)+"' …