保存功能在Tkinter窗口中不起作用

Question

我有一个具有保存和另存为功能的Tkinter程序。 我的“另存为”工作正常，但“另存为”却不能。

但是，每当我按下“保存”按钮时，都会引发错误：NameError：未定义名称“ save_as_dialog”

def save_as():
    notepad_save = notepad.get('1.0', END).strip('\n') 

    head_save = str(head_entry.get().strip('\n')) + '\n' 
    body_save = str(body_entry.get().strip('\n')) + '\n'
    tail_save = str(tail_entry.get().strip('\n')) + '\n'
    legs_save = str(legs_entry.get().strip('\n')) + '\n'


    save_as_dialog = tkfd.asksaveasfilename(initialfile = file_name, 
    initialdir = '/Users/Documents', title = "Save as", defaultextension = 
    '.txt', filetypes = [('Text files', '*.txt')])

with open(save_as_dialog, 'w') as output_file:
   output_file.write(head_save)
   output_file.write(body_save)
   output_file.write(tail_save)
   output_file.write(legs_save)

   output_file.write(notepad_save)

def save():

    notepad_save = notepad.get('1.0', END).strip('\n') 

    head_save = str(head_entry.get().strip('\n')) + '\n' 
    body_save = str(body_entry.get().strip('\n')) + '\n'
    tail_save = str(tail_entry.get().strip('\n')) + '\n'
    legs_save = str(legs_entry.get().strip('\n')) + '\n'

    try:
        with open(save_as_dialog, 'w') as output_file:
            output_file.write(head_save)
            output_file.write(body_save)
            output_file.write(tail_save)
            output_file.write(legs_save)

            output_file.write(notepad_save)

    except NameErrors:
        save_as()

如您所见，该文件在不同的行上存储了不同的信息。 这是程序的关键部分，因此我需要保持该部分不变。 关键是，当我按下保存按钮时，它将引发错误：NameError：未定义名称“ save_as_dialog”。 我尝试过单独使用'except'并使用AttributeError代替，但是它仍然会吐出相同的错误。 我被卡住了！

编辑：我的新代码，仍然无法正常工作：

global save_as_dialog
global opened_file_filename
global filepath

filepath = r"C:\Users\Documents"
opened_file_filename = None

def _open():
    opened_file_filename = tkfd.askopenfilename(title = "Open...", 
    defaultextension = '.txt', filetypes = [('Text files', '*.txt')])

def save_as():
    notepad_save = notepad.get('1.0', END).strip('\n') #

    head_save = head_entry.get().strip('\n') + '\n'  
    body_save = body_entry.get().strip('\n') + '\n'
    tail_save = tail_entry.get().strip('\n') + '\n'
    legs_save = legs_entry.get().strip('\n') + '\n'


    save_as_dialog = tkfd.asksaveasfilename(initialfile = file_name, initialdir 
    = filepath, title = "Save as", defaultextension = '.txt', filetypes = 
    [('Text files', '*.txt')])


    with open(opened_file_filename, 'w') as output_file:
        output_file.write(head_save)
        output_file.write(body_save)
        output_file.write(tail_save)
        output_file.write(legs_save)

        output_file.write(notepad_save)

    opened_file_filename = save_as_dialog

    time_saved_label.config(text = "Saved" )
    print(opened_file_filename)

def save():
    notepad_save = notepad.get('1.0', END).strip('\n') 

    head_save = head_entry.get().strip('\n') + '\n' 
    body_save = body_entry.get().strip('\n') + '\n'
    tail_save = tail_entry.get().strip('\n') + '\n'
    legs_save = legs_entry.get().strip('\n') + '\n'

    if opened_file_filename is None:
        save_as()

    else:
        with open(opened_file_filename, 'w') as output_file:
            output_file.write(head_save)
            output_file.write(body_save)
            output_file.write(tail_save)
            output_file.write(legs_save)

            output_file.write(notepad_save)

    time_saved_label.config(text = "Saved" )
    print(opened_file_filename)

引发错误： 将open（opened_file_filename，'w'）作为output_file：FileNotFoundError：[Errno 2]没有这样的文件或目录：''

Answer 1

那是因为您要在save_as()内部创建save_as_dialog变量。 变量未在save()定义。 在这些函数范围之外声明变量应该是最简单的方法。

我会在包含两个函数的范围内执行诸如save_as_dialog = None ，然后添加

if save_as_dialog is None:
    return save_as()

在save()函数的开始。

结果应该看起来像这样：

from tkinter import filedialog

#  Filename of our file.
opened_file_filename = None


def save_as():
    """
    Opens a file dialog and saves stuff to it.
    :return: None
    """
    global opened_file_filename  # we wanna use the opened_file_filename from global scope

    opened_file_filename = filedialog.askopenfilename()

    with(open(opened_file_filename), 'w') as file:
        # write stuff to file here
        pass


def save():
    """
    If we have a filename, save stuff to it. Otherwise do save_as().
    :return: None
    """
    global opened_file_filename  # we wanna use the opened_file_filename from global scope

    if opened_file_filename is None:
        # it is none, which means we have not chosen a filename yet
        return save_as()

    with(open(opened_file_filename), 'w') as file:
        # write stuff to file here
        pass

# rest of your code