Post Installation Configuration
If your default shell is sh (or possibly anything but bash) you won't be able to access your Anaconda python. If this is your case:
Go to Terminal/Preferences Find 'Shells open with:' Click the button for 'Command (complete path)' Type /bin/bash as path Restart your terminal. When you type $ which python you should now see the anaconda python. For me it was /Users/myname/anaconda3/bin/python.
$ echo $PATH will also change now to show to correct path, with anaconda first:
/Users/myname/anaconda3/bin:/Users/myname/anaconda3/condabin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Library/TeX/texbin:/opt/X11/bin
In Atom I had to add a shebang to the beginning of each script to set this as my preference: #!/Users/myname/anaconda3/bin/python