I productive python development environment is important when you want to use Python to develop applications. Download the right version of Python from https://www.python.org/ and install it.
For example, I downloaded macOS version Python 3.6 and installed it to the machine. I found the software was installed at /Library/Frameworks/Python.framework/Versions/3.6. Relevant commands can be found in the bin folder. The most useful commands are pip3 and python3.
One Pyhton version 3.6 is installed, it can be used in any folder. Just type python3 in command line terminal. You can start interactively execute python statements. If necessary, you can use pip3 to install packages.