Changing the text on a label

Question

I am having trouble with using a key binding to change the value of a label or any parameter  This is my code   from tkinter import   class MyGUI    def   init   self       self   mainWindow   Tk        self fram1   Frame self   mainWindow      self labelText    Enter amount to deposit      self depositLabel   Label self   mainWindow  text   self labelText      self depositEntry   Entry self   mainWindow  width   10      self depositEntry bind   lt Return gt    self depositCallBack      self depositLabel pack       self depositEntry pack        mainloop      def depositCallBack self event       self labelText    change the value      print self labelText   myGUI   MyGUI     When I run this  I click the entrybox and hit enter  hoping that the label will change value to  change the value   However  while it does print that text  the label remains unchanged   From looking at other questions on similar problems and issues  I have figured how to work with some of this outside a class  but I m having some difficulties with doing it inside a class   Also  on a side note  what role does  master  play in tkinter

User · Answer

You can also define a textvariable when creating the Label  and change the textvariable to update the text in the label  Here s an example  labelText   Stringvar   depositLabel   Label self  textvariable labelText  depositLabel grid    def updateDepositLabel txt    you may have to use  args in some cases     labelText set txt   There s no need to update the text in depositLabel manually  Tk does that for you

User · Answer

Here is another one  I think  Just for reference  Let s set a variable to be an instantance of class StringVar     If you program Tk using the Tcl language  you can ask the system to let you know when a variable is changed  The Tk toolkit can use this feature  called tracing  to update certain widgets when an associated variable is modified       There   s no way to track changes to Python variables  but Tkinter   allows you to create variable wrappers that can be used wherever Tk   can use a traced Tcl variable    text   StringVar   self depositLabel   Label self   mainWindow  text   self labelText  textvariable   text                                                                                          def depositCallBack self event         text set  change the value

User · Answer

Use the config method to change the value of the label  top   Tk    l   Label top  l pack    l config text    quot Hello World quot   width    quot 50 quot

User · Answer

I made a small tkinter application which is sets the label after button clicked     usr bin env python from Tkinter import   from tkFileDialog import askopenfilename from tkFileDialog import askdirectory   class Application      def   init   self  master           frame   Frame master width 200 height 200          frame pack            self log file btn   Button frame  text  Select Log File   command self selectLogFile width 25  grid row 0          self image folder btn   Button frame  text  Select Image Folder   command self selectImageFile width 25  grid row 1          self quite button   Button frame  text  QUIT   fg  red   command frame quit width 25  grid row 5           self logFilePath  StringVar           self imageFilePath   StringVar           self labelFolder   Label frame textvariable self logFilePath  grid row 0 column 1          self labelImageFile   Label frame textvariable   self imageFilePath  grid row   1 column 1           def selectLogFile self               filename   askopenfilename               self logFilePath set filename           def selectImageFile self               imageFolder   askdirectory               self imageFilePath set imageFolder   root   Tk   root title  Geo Tagging   root geometry  600x100   app   Application root  root mainloop

User · Answer

There are many ways to tackle a problem like this  There are many ways to do this  I m going to give you the most simple solution to this question I know  When changing the text of a label or any kind of wiget really  I would do it like this   Name Of Label  text      Your New Text    So when I apply this knowledge to your code  It would look something like this   from tkinter import   class MyGUI     def   init   self       self   mainWindow   Tk        self fram1   Frame self   mainWindow      self labelText    Enter amount to deposit      self depositLabel   Label self   mainWindow  text   self labelText      self depositEntry   Entry self   mainWindow  width   10      self depositEntry bind   lt Return gt    self depositCallBack      self depositLabel pack       self depositEntry pack        mainloop      def depositCallBack self event       self labelText  text      change the value      print self labelText   myGUI   MyGUI     If this helps please let me know

User · Answer

self labelText    change the value   The above sentence makes labelText change the value  but not change depositLabel s text  To change depositLabel s text  use one of following setences  self depositLabel  text      change the value   OR self depositLabel config text  change the value

[python] Changing the text on a label

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