Cannot uninstall 'numpy'
One simple solution I found:
sudo -H pip install astropy --ignore-installed numpy
I also had this issue and couldn't get around it in a clean way, but this is what I did:
Inside the Lib folder search "numpy" for an egg_info file (eg. numpy-1.11.0.dev0_2329eae.egg-info).
In my case, this is what Pip was looking at to determine if a current version already exists. I deleted it, then ran normal
pip install numpy
and installed the newest version.
I don't recommend this because I don't understand what it's doing under the hood and it doesn't properly uninstall the old version which could be a recipe for trouble down the line, but if you're desperate like I was then maybe this is a solution for you.
This doesn't directly answer your question, but that's because you're asking the wrong question.
Astropy requires Python 3.5 or 3.6. Trying to get it working with Apple's pre-installed Python 2.7 is a waste of time. You might be able to get an old version working this way, but not by using the installation instructions on astropy.org, and it won't be supported even if you do.
The easy solution is to just Install the latest Anaconda 5.x with Python 3.6, because it comes with Astropy built in.
The almost-as-easy solution is to install Python 3.6 from either a python.org binary installer, or Homebrew, and then use pip3 or, better, python3 -m pip to install everything, as explained on the Astropy install page.
Either way, before doing anything else, you want to get back to a clean slate. In particular, you do not want pip, or any other scripts, attached to Apple's Python 2.7; they will only cause confusion. Assuming you can't reinstall macOS from scratch, the best way to do this is:
- Look in
/Library/Python/2.7/site-packagesand delete everything there except forREADMEandExtras.pth. - Look in
/usr/local/binfor symlinks to anything in thatsite-packages. (If you don't know much about using Unix, try this command:ls -l /usr/local/bin | grep 2.7.) You'll probably havepipandpip2.7here, and probably nothing else. But whatever you have here, delete it.
Now, when you install Python 3.6, the only thing named pip anywhere will be that Python 3.6's pip. You still want to use pip3 or python3 -m pip, but if you screw up and type pip by accident, it won't break anything.
Also, you should strongly consider using a virtual environment. See the Python Packaging Authority's User Guide (or the Anaconda docs, if you went that way) for more on this.