Can't run IDLE with pyenv installation: `Python may not be configured for Tk` `ModuleNotFoundError: No module named _tkinter'

Question

I recently spent couple hours making tkinter and IDLE work on my pyenv Python installation (macOS).

Why you are here?

Answer 1

Here is step by step guide to make IDLE and tkinter work:

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 export 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)