_tkinter.TclError: can't find package Thread

[pobv]

I assume your package would help me a lot, as I try to find/emulate something like an "invokeLater" or "runOnUIThread" for Tkinter in python3 that works on both pypy and cpython (best - that works on any implementation). After installation on pypy3.6.7.1.1 (installation itself worked) I got

$ pypy y.py
Traceback (most recent call last):
  File "y.py", line 4, in <module>
    tkt = TkThread(root)  # make the thread-safe callable
  File "/opt/pypy3.6-7.1.1-beta-linux_x86_64-portable/site-packages/tkthread/__init__.py", line 120, in __init__
    self.root.eval('package require Thread')
  File "/opt/pypy3.6-7.1.1-beta-linux_x86_64-portable/lib_pypy/_tkinter/app.py", line 344, in eval
    self.raiseTclError()
  File "/opt/pypy3.6-7.1.1-beta-linux_x86_64-portable/lib_pypy/_tkinter/app.py", line 168, in raiseTclError
    tklib.Tcl_GetStringResult(self.interp)).decode('utf-8'))
_tkinter.TclError: can't find package Thread

where y.py is the sample on this packages homepage.

from tkthread import tk, TkThread

root = tk.Tk()        # create the root window
tkt = TkThread(root)  # make the thread-safe callable

import threading, time
def run(func):
    threading.Thread(target=func).start()

run(lambda:     root.wm_title('FAILURE'))
run(lambda: tkt(root.wm_title,'SUCCESS'))

root.update()
time.sleep(2)  # _tkinter.c:WaitForMainloop fails
root.mainloop()

I am on Ubuntu 18.04 and have tk-dev installed

 $ dpkg -l | grep tk8
ii  libtk8.6:amd64                         8.6.8-4                                amd64        Tk toolkit for Tcl and X11 v8.6 - run-time files
ii  tk8.6                                  8.6.8-4                                amd64        Tk toolkit for Tcl and X11 v8.6 - windowing shell
ii  tk8.6-blt2.5                           2.5.3+dfsg-4                           amd64        graphics extension library for Tcl/Tk - library
ii  tk8.6-dev:amd64                        8.6.8-4                                amd64        Tk toolkit for Tcl and X11 v8.6 - development files
$ uname -a
Linux x220t 4.15.0-58-generic #64-Ubuntu SMP Tue Aug 6 11:12:41 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=18.04
DISTRIB_CODENAME=bionic
DISTRIB_DESCRIPTION="Ubuntu 18.04.3 LTS"

Any help appreciated.

[serwy]

Try installing the tcl-thread package. I ran into this same issue on Raspbian.

[pobv]

Thanks a lot.
apt-get install tcl-thread
did the trick for python3 (I was only searching for tk, not tcl). And the packages works beautifully with python3, there is almost no delay when updating from a background thread, nice! Exactly what I was looking for, an implementation of runOnUiThread or invokeLater or however it is called in other GUI frameworks.

However, I do not know how to proceed for pypy (where the package is really needed!) and i don't know anything about tcl. I have seen that tcl-thread install also /usr/lib/tcltk/x86_64-linux-gnu/thread2.8.2/libthread2.8.2.so in addition to some tcl files and apparently pypy has its own tcl/tk and still complains about a missing Thread package.

If that works it should really become part of the standard library...

[pobv]

ok, i just blindly copied the entire installation directory of tcl-thread into the pypy installation and that worked.
cp -rp /usr/lib/tcltk/x86_64-linux-gnu/thread2.8.2 /opt/pypy3.6-7.1.1-beta-linux_x86_64-portable/lib/tcl/
Might not be clean, but I don't complain. It works as smoothly and fast under pypy as under python3.

Having tkt in the standard (or call it invoke_later or whatever) would make tkinter much more usable for all people that do know other UI frameworks and threading. Thanks for the package.

[Jakar510]

Is there a way to get this working on Windows 10, as it is in Linux shown above?