Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Installation

Tkinter should be available by default after Python is installed. However, please continue read if you encounter the following error.

import _tkinter # If this fails your Python may not be configured for Tk ImportError: No module named _tkinter

1. On macOS, installing python-tk might fix the issue.

   brew install python-tk
   

General Tips

1. You need to use multithreading to make GUI application more responsive if any event triggers a long-run task. Please refer to Concurrency and Parallel Computing in Python for more discussions.

2. When you develop a GUI application using Tkinter in Python, root = tk.Tk() must be the first statement after imports.

   import tkinter as tk
   import ...
   root = tk.Tk()
   ...
   

3. It is suggested that you use the ttk module (Tk Themed Widgets) when possible. It has more advanced and better looking widgets. However, the Text widget is only available in tk.

4. It is suggested that you name a widget using the name option when creating it, and use the name to refer to the widget later. Avoid keeping referencing to widgets by yourself!

   root.nametowidget("name1.name2.name3")
   

5. A Button object has the option command to set a callback function when clicked while a Label object does not have this option.

   def button_click():
       ...
   
   Button(root, text="Scrrenshot", command=button_click)
   

   Nevertheless, you can bind a callback function to any widget using the method widget_obj.bind.

   import tkinter as tk
   root = tk.Tk()
   
   def label_left_click(event):
       ...
   
   label = tk.Label(root, text="my label")
   label.bind("<Button-1>", label_left_click)
   

   A few things to keep in mind. When you bind a callback function using the command option, the callback function takes no argument. However, when you bind a call back function using the method widget_obj.bind, the callback function takes an Event object as argument.

6. To make a label visible no matter there are text/image in it or not, you can set a border to it.

   label = tk.Label(root, bd=1)
   

   You can ke it even more visible by giving a sunken effect.

   label = tk.Label(root, bd=1, relief=tk.SUNKEN)
   

7. A Frame object has its own grid. This makes frames and grid the best combinations to manage the layout of your GUI application. You can use frames to group components. Inside each frame, use grid to control the layout of widgets.

8. It seems to me that you must keep a reference to a PhotoImage object in order to use it for a label. A temporary PhotoImage object does not work. The image object can then be used wherever an image option is supported by some widget (e.g. labels, buttons, menus). In these cases, Tk will not keep a reference to the image. When the last Python reference to the image object is deleted, the image data is deleted as well, and Tk will display an empty box wherever the image was used.

9. There are 2 kinds of PhotoImage objects that you can use with Tkinter. The first is Tkinter.PhotoImage while the second is PIL.ImageTk.PhotoImage. The latter is preferred as it is more flexible, supports more data format, and is easier to use. Tkinter.PhotoImage supports only GIF pictures if you use the file option to load an image, and it seems to me that it does not accept PIL.Image.

Size of Widgets

https://stackoverflow.com/questions/17398926/how-to-set-a-widgets-size-in-tkinter/17399180

Grid

Set minimum size of rows and columns of the grid.

col_count, row_count = root.grid_size()
for col in xrange(col_count):
    root.grid_columnconfigure(col, minsize=20)
for row in xrange(row_count):
    root.grid_rowconfigure(row, minsize=20)

https://stackoverflow.com/questions/28019402/tkinter-grid-spacing-options

Bind Keys

https://effbot.org/tkinterbook/tkinter-events-and-bindings.htm

Keyboard events are sent to the focused widget.

widget.bind("<Key>", callback_func)

Tutorials

https://www.youtube.com/playlist?list=PL6gx4Cwl9DGBwibXFtPtflztSNPGuIB_d

References

• The Checkbutton Widget in Tkinter

• The Entry Widget in Tkinter

• The Label Widget in Tkinter

• Tkinter: “Python may not be configured for Tk”

• https://docs.python.org/3/library/tkinter.html

• https://docs.python.org/3/library/tk.html

• http://effbot.org/tkinterbook/

• http://stupidpythonideas.blogspot.com/2013/10/why-your-gui-app-freezes.html

• https://www.reddit.com/r/Python/comments/7rp4xj/threading_a_tkinter_gui_is_hell_my_least_favorite/