INSTALLING PYQT5 ON A MACOS10.14.6 SYSTEM INTRODUCTION I had an old python program, which only runs with pyqt5. After I upgraded homebrew some old versions of software where removed and then I uninstalled my working python2.7 version by "brew uninstall python@2" and tried to reinstall it via "brew install python@2". But I had to realize that python2 is no longer maintained by homebrew. After many struggles with homebrew, pipenv and virtualenv I came to the point to use pyenv, which installs each python version and its modules in a separate environment. Further I had to struggle to compile pyqt5, because it is no longer maintained by the installation program pip of python. Now, I write down the steps to install python2.7 and pyqt5 on a macos mojave 10.14.6 system, in case other people are interested. INSTALLATION 1. install pyenv: curl https://pyenv.run | bash pyenv install 2.7.18 -> this installed python2.7 into /Users/felixvoigt/.pyenv/versions/2.7.18 2. install sip: download sip4.19.25.tar.gz from https://www.riverbankcomputing.com/software/sip/download into ~/documents/tmp and unpack it. cd ~/documents/tmp/sip-4.19.25 ~/.pyenv/versions/2.7.18/bin/python2.7 configure.py --sip-module=PyQt5.sip (the option --sip-module... is important, otherwise pyqt5 will not find sip) make make install 3. install pyqt5: first I had to upgrade Xcode from version 9.0 to 11.3. then I downloaded PyQt5-5.15.4.tar.gz from https://pypi.org/project/PyQt5/#files into ~/documents/tmp and unpacked it. cd ~/documents/tmp/PyQt5-5.15.4 ~/.pyenv/versions/2.7.18/bin/python2.7 configure.py --qmake /usr/local/Cellar/qt@5/5.15.2/bin/qmake --sip=/Users/felixvoigt/.pyenv/versions/2.7.18/bin/sip --verbose (the options --qmake..., --sip... are important, otherwise you will obtain errors, adopt the paths to your own ones) make make install Now, pyqt5 should be installed on your mac system. You can install other modules via "~/.pyenv/versions/2.7.28/bin/pip2.7 install module_x", where module_x is the name of the module. The following web links where helpful to me: https://gist.github.com/fredrikaverpil/52dc5b2cdcb17001c7b0c13bdba4d494, http://python.6.x6.nabble.com/private-sip-td5235854.html. Maybe I missed some steps in the description, because I had done it for myself some time ago, and I had many trials and errors. So, if you find something is missing in the description or you have questions feel free to write an e-mail to me (e-mail address in Impressum).