I use Atom in this way:
1) Setup SAMBA sharing the directories you want to access
2) In Finder the Pi will appear as an external drive
3) Click on the drive and provide your Pi user and password to connect to
4) Save these into Keychain for future use
Sometimes Finder will report it cannot find the Pi (not at this location) - you can either kill Finder from Terminal or restart the Mac. I’ve never got to the bottom of this but found the most reliable way to stop this from happening is to have one or more SSH sessions to the Pi Open first and given that my current work is not GUI this suits me fine
I also use FileZilla using SSH transfer mode to pull the programs back to the Mac so TimeMachine backs them up. I miss the auto backup I had set up in Nano and must look at setting this up in Atom
I do not run the Python scripts on my Mac as I need the GPIO etc. but had a virtual machine under Fusion running Raspbian Desktop with 2Gb and 1 core at one point and that worked fine for some Python work as well.