title: Why is permission denied on pip install except for when "--user" is included at end of command?
body: <p>I use pip install to install various python packages on my Mac OS terminal. If I don't include "--user" at the end, I am consistently notified that there was an "EnvironmentError: [Errno 13] Permission Denied". However, if I include --user at the end, I am able to install packages. However, on other Apple computers I use the Terminal and Python for, I have no trouble installing packages and I do not need to add "--user" to the end.</p>
  
  <p>Why the difference here? Why do I need to include --user to the end of my pip install commands for one Mac laptop but not for others?</p>