Thank you, Etresoft, for your response. So you have successfully installed the scipy package for Python3 on Catalina? How did you do it? This isn't a Homebrew problem, but a Catalina problem. I was using Homebrew as the solution to install python3. If I install CLT from https://developer.apple.com/download/more/?=command%20line%20tools and then run $pip3 install scipy I get an error saying "ERROR: Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/Library/Python/3.8'" The same for numpy. I'm using an admin account. If I can't install common python packages, I can't get a useable implementation of python3 on Catalina. This was not a problem for previous OS versions. Does anyone else have this problem?

Thanks again, Etresoft, for your reply. Without Homebrew: If I install CLT from https://developer.apple.com/download/more/?=command%20line%20tools and then run  $pip3 install scipy I get an error saying "ERROR: Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/Library/Python/3.8'" The same for numpy. I'm using an admin account. If I can't install common python packages, I can't get a useable implementation of python3 on Catalina. This was not a problem for previous OS versions. Does anyone else have this problem?

I now have a working version of python3. Here's the steps in case anyone else has problems. Install Xcode (make sure to open and accept license) Install CLT from https://developer.apple.com/download/more/?=command%20line%20tools (otherwise software not found error with $ xcode-select --install) Install Homebrew brew install python (adds 3.9) add '/usr/local/opt/python@3.9/libexec/bin' to $PATH fix openblas with: $ export LDFLAGS="-L/usr/local/opt/openblas/lib"  and $ export CPPFLAGS="-I/usr/local/opt/openblas/include" 7. use pip3 to install packages I'm still interested in a non-Homebrew solution if such a thing is available. Never found one . . .