Python TypeError:+:' NoneType'不支持的操作数类型和' str'

时间:2015-09-06 21:17:36

标签: python

在询问我的问题之前,我已经调查了这个问题,但是我找不到符合我情况的任何东西。

我正在编写一个Python程序 - 一个文本编辑器;使用Python和Gtk + 3。

以下是我遇到的错误:

Traceback (most recent call last):
  File "file.py", line 58, in on_s_pressed
    if (self.set_title == (filename + " - DeSedit")):
TypeError: unsupported operand type(s) for +: 'NoneType' and 'str'

这是我的代码:

#!/usr/bin/env python3

from gi.repository import Gtk, Gdk

class DeSedit(Gtk.Window):
    def __init__(self):
        Gtk.Window.__init__(self, title="DeSedit")

    self.set_default_size(650, 500)

    # keyboard shortcuts
    """ <Control>O """
    accel = Gtk.AccelGroup()
    accel.connect(Gdk.keyval_from_name('O'), Gdk.ModifierType.CONTROL_MASK, 0, self.on_o_pressed)
    self.add_accel_group(accel)
    """ <Control>S """
    accel1 = Gtk.AccelGroup()
    accel1.connect(Gdk.keyval_from_name('S'), Gdk.ModifierType.CONTROL_MASK, 0, self.on_s_pressed)
    self.add_accel_group(accel1)

    # grid to organize widgets
    self.box = Gtk.Box()
    self.add(self.box)
    # text view
    self.textview = Gtk.TextView()
    self.textview.set_wrap_mode(True)
    self.textbuffer = self.textview.get_buffer()
    # scroll bar
    scrollwindow = Gtk.ScrolledWindow()
    scrollwindow.add(self.textview)
    self.box.pack_start(scrollwindow, True, True, 0)

# open file dialog
def on_o_pressed(self, *args):
    openDialog = Gtk.FileChooserDialog("Select file to be opened", self,
        Gtk.FileChooserAction.OPEN,
        (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
        Gtk.STOCK_OPEN, Gtk.ResponseType.OK))
    response = openDialog.run()
    if response == Gtk.ResponseType.OK:
        filename = openDialog.get_filename()
        with open(filename, 'r') as fRead:
            data = fRead.read()
            self.textbuffer.set_text(data)
            self.set_title(filename + " - DeSedit")
            fRead.close()
        openDialog.destroy()
    elif response == Gtk.ResponseType.CANCEL:
        openDialog.destroy()

# save file dialog
def on_s_pressed(self, *args):
    saveDialog = Gtk.FileChooserDialog("Select folder to save file", self,
        Gtk.FileChooserAction.SAVE,
        (Gtk.STOCK_CANCEL, Gtk.ResponseType.CANCEL,
        Gtk.STOCK_SAVE, Gtk.ResponseType.OK))
    filename = saveDialog.get_filename()
    if self.set_title == (filename + " - DeSedit"):
        print("hmm")
    response = saveDialog.run()
    if response == Gtk.ResponseType.OK:

        with open(filename, 'w') as fWrite:
            data = self.textbuffer.get_text(self.textbuffer.get_start_iter(),
                                            self.textbuffer.get_end_iter(), True)
            fWrite.write(data)
            fWrite.close()
        saveDialog.destroy()
    elif response == Gtk.ResponseType.CANCEL:
        saveDialog.destroy()



window = DeSedit()  # create DeSedit object
window.connect("delete-event", Gtk.main_quit)
window.show_all()
Gtk.main()

2 个答案:

答案 0 :(得分:2)

它基本上告诉你filename是一个NoneType对象,这意味着saveDialog.get_filename()退回None

根据the doc,这意味着没有选择任何文件

  

gtk.FileChooser.get_filename

     

def get_filename()

     

返回:     当前选择的文件名,如果没有选择文件则为无,或者所选文件不能用本地文件名表示。

答案 1 :(得分:1)

您的文件名来自:

filename = saveDialog.get_filename()

函数由于某种原因返回None(可能是因为用户取消了对话框 - 当你取消Tkinter文件对话框时,你得到一个空字符串),然后尝试将它与字符串组合,这不能完成。添加一些错误处理代码来处理没有选择文件名的情况,例如if not filename: return或其他。