Unfortunately, there isn't another way from the command line other than installing Homebrew, an unofficial package manager for macOS and then typing
brew install python3.
This method does pose some issues. When installing Python via Homebrew, it does not remove any old version of Python (for compatibility reasons). This means old versions could be sitting on your hard drive, taking up space that could be used for something else. Another possible issue with Homebrew is that it needs Xcode to be installed so that it can compile and install Python on-device (and the current version of Xcode takes up 10+ gigs of HD space, not to factor in the space to store the source code).
The preferred and official way to install Python is via their
.pkg installer available at their website, but this doesn't remove old Python3 installations either (again, for the same reasons).
So it all comes down to how you want to go about installing Python. There are many different ways, and I only listed the ones that seem most relevant to your situation.