kivy : TypeError: 'NoneType' object is not subscriptable in python
kivy : TypeError: 'NoneType' object is not subscriptable in python
当我 运行 这段代码时，它显示“TypeError: 'NoneType' object is not subscriptable”。
我想在单击按钮时切换到其他屏幕
我正在制作一个小程序，我 运行 进入错误“TypeError：'NoneType' object is not subscriptable。
我以前从未见过这个错误，所以我不知道它是什么意思。
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager , Screen
#define our different screens
class StartTestBtn(Screen):
pass
class TestsResultBtn(Screen):
pass
class SettingBtn(Screen):
pass
class ContactUsBtn(Screen):
pass
class MainPage(Screen):
pass
class WindowManager(ScreenManager):
pass
class MyGridLayout(Widget):
pass
Builder.load_string("""
#:import utils kivy.utils
WindowManager:
MainPage:
StartTestBtn:
TestsResultBtn:
SettingBtn:
ContactUsBtn:
<MainPage>:
name:"main page"
BoxLayout:
cols:1
size: root.width , root.height
spacing: 20
padding: 150
Label:
text: "Welcom"
font_size:72
Button:
text: "start Test"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "startTestBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Tests result"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "TestsResultBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Setting"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "SettingBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Contact Us"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "contactUsBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
<StartTestBtn>:
name: "startTestBtn"
Label:
Text: "start"
font_size: 72
<TestsResultBtn>:
name: "TestsResultBtn"
Label:
Text: "start"
font_size: 72
<SettingBtn>:
name: "SettingBtn"
Label:
Text: "start"
font_size: 72
<ContactUsBtn>:
name: "contactUsBtn"
Label:
Text: "contact"
font_size: 72
""")
class MyLayout(Widget):
pass
class Shenacell(App):
def build(self):
return MyLayout()
if __name__ == '__main__' :
Shenacell().run()
这是一个错误 :
Traceback (most recent call last):
File "f:/venv/nowornever/Scripts/gui_python.py", line 32, in <module>
Builder.load_string("""
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\builder.py", line 373,
in load_string
parser = Parser(content=string, filename=fn)
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\parser.py", line 402, in __init__
self.parse(content)
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\parser.py", line 511, in parse
objects, remaining_lines = self.parse_level(0, lines)
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\parser.py", line 674, in parse_level
if current_property[:3] == 'on_':
TypeError: 'NoneType' object is not subscriptable
您的 kv 文件以 5 个空格的缩进开头，因此您必须在整个 kv 文件中继续使用该缩进大小。 kv 的最后一节缩进不正确，属性 名称无效（Text 应为 text）。这是您的 kv:
的更正版本
#:import utils kivy.utils
WindowManager:
MainPage:
StartTestBtn:
TestsResultBtn:
SettingBtn:
ContactUsBtn:
<MainPage>:
name:"main page"
BoxLayout:
cols:1
size: root.width , root.height
spacing: 20
padding: 150
Label:
text: "Welcom"
font_size:72
Button:
text: "start Test"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "startTestBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Tests result"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "TestsResultBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Setting"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "SettingBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Contact Us"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "contactUsBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
<StartTestBtn>:
name: "startTestBtn"
Label:
text: "start"
font_size: 72
<TestsResultBtn>:
name: "TestsResultBtn"
Label:
text: "start"
font_size: 72
<SettingBtn>:
name: "SettingBtn"
Label:
text: "start"
font_size: 72
<ContactUsBtn>:
name: "contactUsBtn"
Label:
text: "contact"
font_size: 72
新固定码
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager , Screen
#define our different screen
class StartTestBtn(Screen):
pass
class TestsResultBtn(Screen):
pass
class SettingBtn(Screen):
pass
class ContactUsBtn(Screen):
pass
class MainPage(Screen):
pass
class WindowManager(ScreenManager):
pass
class MyGridLayout(Widget):
pass
Builder.load_string("""
#:import utils kivy.utils
<WindowManager>:
MainPage:
StartTestBtn:
TestsResultBtn:
SettingBtn:
ContactUsBtn:
<MainPage>:
name:"main page"
BoxLayout:
cols:1
size: root.width , root.height
spacing: 20
padding: 150
Label:
text: "Welcom"
font_size:72
Button:
text: "start Test"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "startTestBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Tests result"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "TestsResultBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Setting"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "SettingBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Contact Us"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "contactUsBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
<StartTestBtn>:
name: "startTestBtn"
Label:
text: "start"
font_size: 72
<TestsResultBtn>:
name: "TestsResultBtn"
Label:
text: "start"
font_size: 72
<SettingBtn>:
name: "SettingBtn"
Label:
text: "start"
font_size: 72
<ContactUsBtn>:
name: "contactUsBtn"
Label:
text: "contact"
font_size: 72
""")
class MyLayout(Widget):
pass
class Shenacell(App):
def build(self):
return WindowManager()
if __name__ == '__main__' :
Shenacell().run()
当我 运行 这段代码时，它显示“TypeError: 'NoneType' object is not subscriptable”。 我想在单击按钮时切换到其他屏幕 我正在制作一个小程序，我 运行 进入错误“TypeError：'NoneType' object is not subscriptable。 我以前从未见过这个错误，所以我不知道它是什么意思。
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager , Screen
#define our different screens
class StartTestBtn(Screen):
pass
class TestsResultBtn(Screen):
pass
class SettingBtn(Screen):
pass
class ContactUsBtn(Screen):
pass
class MainPage(Screen):
pass
class WindowManager(ScreenManager):
pass
class MyGridLayout(Widget):
pass
Builder.load_string("""
#:import utils kivy.utils
WindowManager:
MainPage:
StartTestBtn:
TestsResultBtn:
SettingBtn:
ContactUsBtn:
<MainPage>:
name:"main page"
BoxLayout:
cols:1
size: root.width , root.height
spacing: 20
padding: 150
Label:
text: "Welcom"
font_size:72
Button:
text: "start Test"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "startTestBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Tests result"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "TestsResultBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Setting"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "SettingBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Contact Us"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "contactUsBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
<StartTestBtn>:
name: "startTestBtn"
Label:
Text: "start"
font_size: 72
<TestsResultBtn>:
name: "TestsResultBtn"
Label:
Text: "start"
font_size: 72
<SettingBtn>:
name: "SettingBtn"
Label:
Text: "start"
font_size: 72
<ContactUsBtn>:
name: "contactUsBtn"
Label:
Text: "contact"
font_size: 72
""")
class MyLayout(Widget):
pass
class Shenacell(App):
def build(self):
return MyLayout()
if __name__ == '__main__' :
Shenacell().run()
这是一个错误 :
Traceback (most recent call last):
File "f:/venv/nowornever/Scripts/gui_python.py", line 32, in <module>
Builder.load_string("""
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\builder.py", line 373,
in load_string
parser = Parser(content=string, filename=fn)
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\parser.py", line 402, in __init__
self.parse(content)
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\parser.py", line 511, in parse
objects, remaining_lines = self.parse_level(0, lines)
File "C:\Users\Asus\AppData\Roaming\Python\Python38\site-packages\kivy\lang\parser.py", line 674, in parse_level
if current_property[:3] == 'on_':
TypeError: 'NoneType' object is not subscriptable
您的 kv 文件以 5 个空格的缩进开头，因此您必须在整个 kv 文件中继续使用该缩进大小。 kv 的最后一节缩进不正确，属性 名称无效（Text 应为 text）。这是您的 kv:
#:import utils kivy.utils
WindowManager:
MainPage:
StartTestBtn:
TestsResultBtn:
SettingBtn:
ContactUsBtn:
<MainPage>:
name:"main page"
BoxLayout:
cols:1
size: root.width , root.height
spacing: 20
padding: 150
Label:
text: "Welcom"
font_size:72
Button:
text: "start Test"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "startTestBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Tests result"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "TestsResultBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Setting"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "SettingBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Contact Us"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "contactUsBtn"
size_hint: {'center_x': 0.5}
size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
<StartTestBtn>:
name: "startTestBtn"
Label:
text: "start"
font_size: 72
<TestsResultBtn>:
name: "TestsResultBtn"
Label:
text: "start"
font_size: 72
<SettingBtn>:
name: "SettingBtn"
Label:
text: "start"
font_size: 72
<ContactUsBtn>:
name: "contactUsBtn"
Label:
text: "contact"
font_size: 72
新固定码
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager , Screen
#define our different screen
class StartTestBtn(Screen):
pass
class TestsResultBtn(Screen):
pass
class SettingBtn(Screen):
pass
class ContactUsBtn(Screen):
pass
class MainPage(Screen):
pass
class WindowManager(ScreenManager):
pass
class MyGridLayout(Widget):
pass
Builder.load_string("""
#:import utils kivy.utils
<WindowManager>:
MainPage:
StartTestBtn:
TestsResultBtn:
SettingBtn:
ContactUsBtn:
<MainPage>:
name:"main page"
BoxLayout:
cols:1
size: root.width , root.height
spacing: 20
padding: 150
Label:
text: "Welcom"
font_size:72
Button:
text: "start Test"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "startTestBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Tests result"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "TestsResultBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Setting"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "SettingBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
Button:
text: "Contact Us"
font_size: 32
size_hint_x: None
height:50
size_hint_y: None
width:200
on_release: app.root.current = "contactUsBtn"
#size_hint: {'center_x': 0.5}
#size_hint: (.5,.5)
background_color : (34/255.0,59/255.0,74/255.0,1)
<StartTestBtn>:
name: "startTestBtn"
Label:
text: "start"
font_size: 72
<TestsResultBtn>:
name: "TestsResultBtn"
Label:
text: "start"
font_size: 72
<SettingBtn>:
name: "SettingBtn"
Label:
text: "start"
font_size: 72
<ContactUsBtn>:
name: "contactUsBtn"
Label:
text: "contact"
font_size: 72
""")
class MyLayout(Widget):
pass
class Shenacell(App):
def build(self):
return WindowManager()
if __name__ == '__main__' :
Shenacell().run()