TL;DR

• Perhaps ok for small, one-file utility apps.

Pros

• Comes out of the box with Python.

Cons

• Look and feel are a real buzzkill on Linux, possibly also on other platforms—even with themed widgets. The ugliness of menus is pretty much a deal killer
• No standard GUI builder, though a few 3rd party ones exist.

tkdemo.py

from tkinter import *
from tkinter import ttk
 
def do_nothing():
    print('passssss ...')
 
root = Tk()
root.option_add('*tearOff', False)
s=ttk.Style()
s.theme_use('clam')
 
# Menubar
menubar = Menu(root)
root.config(menu=menubar)
 
filemenu = Menu(menubar)
filemenu.add_command(label='New ...', accelerator='Ctrl + N', command=do_nothing)
filemenu.add_command(label='Open ...', accelerator='Ctrl + O', command=do_nothing)
filemenu.add_separator()
filemenu.add_command(label='Quit', accelerator='Ctrl + Q', command=root.destroy)
 
editmenu = Menu(menubar)
editmenu.add_command(label='Copy', accelerator='Ctrl + C', command=do_nothing)
editmenu.add_command(label='Cut', accelerator='Ctrl + X', command=do_nothing)
editmenu.add_command(label='Paste', accelerator='Ctrl + V', command=do_nothing)
 
menubar.add_cascade(label='File', menu=filemenu)
menubar.add_cascade(label='Edit', menu=editmenu)
 
# Toolbar
toolbar = ttk.Frame(root)
 
tb_foo = ttk.Button(toolbar, text='Foo', command=do_nothing)
tb_foo.pack(side=LEFT, padx=2, pady=2)
tb_bar = ttk.Button(toolbar, text='Bar', command=do_nothing)
tb_bar.pack(side=LEFT, padx=2, pady=2)
 
toolbar.pack(side=TOP, fill=X)
 
# Status bar
status = ttk.Label(root, text='System status: doing nothing', borderwidth=2, relief=SUNKEN, anchor=W)
status.pack(side=BOTTOM, fill=X)
 
# Go!
root.mainloop()

TL;DR

• Perhaps best option for Linux-centric apps—unless/until some GNOME heaviness/goofiness happens.

Replacing PyGTK.

Pros

• Workflow (UI layout to code) is pleasant.
• First-class Linux framework.
• LGPL
• Nice support for externally defined UIs.
• Nice UI builder.
• Potentially tons of GNOME stuff to leverage.
• Code seems grainy but otherwise understandable.
• Easy to install if using distro packages.

Neutral/undecided

• Event handling is simple event→callback; no “listener” or signal/slot concepts.
• Event names are specified as strings.

Cons

• Poor support on other operating systems.
• GTK3 is the future and it is built for GNOME. For other desktop environments, who knows how well it will work and what will be supported. Will a ton of GNOME dependencies eventually be required?

TL;DR

• Perhaps best option for multi-platform proprietary apps that have zero budget.

Pros

• Liberal license.
• True multi-platform support (e.g., native icons, native order dialog buttons).
• ? install (suspect easy if distro repos are used)

Cons

• Support for Python 3 via Phoenix is still raw.
• Second-class Linux framework.
• Wonky UI builder support
  • Requires third-party tools:
    • wxFormBuilder needs to be built (generally not in repos), generates .fbp files, which are XML but not really human readable.
    • wxGlade is incomplete.
    • wxSmith is integrated with Code::Blocks.
  • No UI file format results in slightly awkward UI file export/import mechanism: export a class with UI builder, subclass it in the app to make your wired-up window.
• Code seems awkward at times (perhaps it's only oddly named components)

Awkward points:

• In wxville, a Frame is a window, a Window is the mega-parent class, a Control is a widget.
• Method names are CamelCase (first capitalized).
• Events: self.Bind(event-type, handler, emitting-object)

TL;DR

• Perhaps best option for multi-platform FOSS apps and for proprietary apps that have a $500 tools budget.

Pros

• First class Linux framework.
• Excellent multiplatform support (except maybe non-GNOME GTK).
• Lots of components (including “we do it differently” DBUS, etc.)
• Used by Spyder and a lot of others.

Cons:

• GPL-only or commercial license is at ~$500. (PySide is LGPL, but there has been little development.)
• Qt code can be heavy, somewhat verbose.
• Possibly PITA to install if not using distro repos (which you want because it moves so fast).¹⁾

TL;DR

• Interesting, but not really a desktop application framework. Good for touch interfaces.

Pros

• MIT license.

Needs research

Pros

• LGPL

Is a wrapper around desktop toolkits. On Linux, wraps PyGTK right now, PyGObject in the future.