Install python with tk supported via pyenv on macOS.

install-python-with-tk-supported-via-pyenv-on-macos.sh

#!/usr/bin/bash
# https://github.com/pyenv/pyenv/issues/1375#issuecomment-524280004

# NOTE: following steps does work on my macOS 10.15.4, pyenv 1.2.18 :(
# Error example:
# ERROR: invalid Python executable: /Users/weaming/.pyenv/versions/3.8.2/bin/python3.8
# The python-build could not find proper executable of Python after successful build. 

# Finally solution: download .pkg installer from https://www.python.org/downloads/release/python-382/
# it includes its own private version of Tcl/Tk 8.6. It does not use any system-supplied or third-party supplied versions of Tcl/Tk.

brew update
brew upgrade pyenv
brew install tcl-tk

# replace text in $(which python-build)
# $CONFIGURE_OPTS ${!PACKAGE_CONFIGURE_OPTS} "${!PACKAGE_CONFIGURE_OPTS_ARRAY}" || return 1
# with
# $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' ${!PACKAGE_CONFIGURE_OPTS} "${!PACKAGE_CONFIGURE_OPTS_ARRAY}" || return 1

pyenv uninstall 3.8.2
# provide executable `python` to `python-build`: or else will raise error "python-build could not find proper executable of Python after successful build"
pyenv global system

# How to support PyInstaller: https://github.com/pyinstaller/pyinstaller/wiki/FAQ#mac-os-x
# but `--enable-shared` did not work, it's using tcl-tk version 8.5 which is not the latest 8.6 installed via brew
# Using `---enable-framework` works! What is it? See https://stackoverflow.com/a/15057523
PYTHON_CONFIGURE_OPTS="--enable-framework" pyenv install 3.8.2

# install XQuartz from https://www.xquartz.org to display X window
# test if it works
python -m tkinter -c 'tkinter._test()'