Python/Tkinter : ModuleNotFoundError: No module named '_tkinter'

Question

This is my first post StackOverflow, I will try to make it as correct and complete as possible if you have any tips to improve my post I will gladly accept it.

I'm having trouble running code written in Python that uses Tkinter.

I will try to describe in detail my actions to facilitate the identification of the error.

I started a course at Coursera on DSP (Digital Signal Processing) where it is suggested to install a tool written in python (and a little bit of C). I'm using Arch Linux.

link on Github: sms-tools repo

Using pyenv/virtualenv/virtualenvwrapper I created an environment with Python 3.7.5, as recommended in the "How to use" section of the repository.

I installed the required libraries in my environment by pip:

%pip install ipython numpy matplotlib scipy cython

I compiled some C functions in the "/sms-tools/software/models/utilFunctions_C"

directory with the following command:

%python compileModule.py build_ext --inplace

Finally, I run the models GUI in the directory "/sms-tools/software/models_interface"

%python models_GUI.py

and I get the following message:

Traceback (most recent call last):
  File "models_GUI.py", line 6, in <module>
    from Tkinter import *   ## notice capitalized T in Tkinter 
ModuleNotFoundError: No module named 'Tkinter'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "models_GUI.py", line 9, in <module>
    from tkinter import *   ## notice lowercase 't' in tkinter here
  File "~/.pyenv/versions/3.7.5/lib/python3.7/tkinter/__init__.py", line 36, in <module>
    import _tkinter # If this fails your Python may not be configured for Tk
ModuleNotFoundError: No module named '_tkinter'

I will now describe some of my attempts to solve the problem:

Looking at Tkinter section in Python Wiki I tried installing Tcl and Tk.

%sudo pacman -S tk

but it was already installed. after that I tried installing with pip:

%pip install tk

and

%pip install tkinter

and the error remains the same.

I also tried to create a symlink with this code: %ln -s /usr/lib/python3.8/lib-dynload/_tkinter.cpython-38-x86_64-linux-gnu.so _tkinter.cpython-38-x86_64-linux-gnu.so

the symlink was created in the following folders:

~/.ve/Coursera_DSP/lib/python3.7/lib-dynload

and

.pyenv/versions/3.7.5/lib/python3.7/lib-dynload

But I still get the same error.

I appreciate it if anyone has any suggestions and I apologize for the language errors since English is not my mother tongue.

After an incessant search on the internet, I believe the problem is related to pyenv and TCL/TK. I don't understand much about the subject but I suspect that in the creation of the environment by virtualenv python has lost the connection with TCL/TK. Does that make any sense?

Answer 1

Here is step by step guide to make IDLE and tkinter work. Working for me on macOS Catalina. Should be easily adapted to Linux environment:

1. install tcl-tk with Homebrew. In shell run brew install tcl-tk
2. in shell run echo 'export PATH="/usr/local/opt/tcl-tk/bin:$PATH"' >> ~/.zshrc
3. reload shell by quitting Terminal app or run source ~/.zshrc
4. after reloaded check that tck-tk is in $PATH. Run echo $PATH | grep --color=auto tcl-tk. As the result you should see your $PATH contents with tcl-tk highlighted
5. now we run three commands from Homebrew's output from step #1
   1. in shell run export LDFLAGS="-L/usr/local/opt/tcl-tk/lib"
   2. in shell run export CPPFLAGS="-I/usr/local/opt/tcl-tk/include"
   3. in shell run export PKG_CONFIG_PATH="/usr/local/opt/tcl-tk/lib/pkgconfig"
6. if you have your Python version already installed with pyenv then uninstall it with pyenv uninstall <your python version>. E.g. pyenv uninstall 3.8.2
7. set environment variable that will be used by python-build. In shell run PYTHON_CONFIGURE_OPTS="--with-tcltk-includes='-I/usr/local/opt/tcl-tk/include' --with-tcltk-libs='-L/usr/local/opt/tcl-tk/lib -ltcl8.6 -ltk8.6'" Note: in future use tck-tk version that actually installed with Homebrew. At the moment of posting 8.6 was the actual
8. finally install Python with pyenv with pyenv install <version>. E.g. pyenv install 3.8.2

Test

1. in shell run pyenv global <verion that you've just installed>
2. now check IDLE. In shell run idle. You should see IDLE window without any warnings and "text printed in red".

3. now check tkinter. In shell run python -m tkinter -c "tkinter._test()". You should see test window like on the image:

That's it!

My environment:

check this is something went wrong executing steps above:

1. macOS Catalina
2. zsh (included in macOS Catalina) = "shell" above
3. Homebrew (installed with instructions from Homebrew official website)
4. pyenv (installed with Homebrew and PATH updated according to pyenv official readme from GitHub)
5. Python 3.8.x - 3.9.x (installed with pyenv install <version> command)