Python TypeError：不支持的操作數類型爲+：'NoneType'和'str'

-1

我在問我的問題之前已經查看了這個，但一直沒有找到符合我的情況的東西。Python TypeError：不支持的操作數類型爲+：'NoneType'和'str'

我正在寫一個Python程序 - 一個文本編輯器;使用Python和Gtk + 3。

這是我得到的錯誤：

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'

這裏是我的代碼：

#!/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()

來源

2015-09-06 DevRobot

這樣看來，'saveDialog.get_filename（）'將返回無。 –

這一個不提供[mcve]（ref：http://meta.stackoverflow.com/q/306049/3001761） – jonrsharpe

你的文件名從這裏走過：

filename = saveDialog.get_filename()

函數返回None出於某種原因（可能是因爲用戶取消了對話框 - 當您取消Tkinter文件對話框時，您將獲得一個空格y字符串），然後試圖將它與一個字符串結合起來，這是無法完成的。放入一些錯誤處理代碼來處理沒有選擇文件名的情況，如if not filename: return或其他。

來源

2015-09-06 21:23:39 TigerhawkT3

它基本上告訴你filename是一個NoneType對象，意思是saveDialog.get_filename()返回None。

根據the doc這意味着沒有文件被選中

gtk.FileChooser.get_filename

def get_filename()

Returns : The currently selected filename, or None if no file is >selected, or the selected file can't be represented with a local filename.

來源

2015-09-06 21:24:04

Python TypeError：不支持的操作數類型爲+：'NoneType'和'str'

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