MuhsinFatih/pythondoneright.md

## pythondoneright.md

      
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              pythondoneright.md
            
          
    I am assuming you are here because like me, you installed a bazillion different python interpreters on mac and the whole thing is a spagetti.
Today, I finally fixed my python installation. Whatever I install for python2 or python3 using pip JUST.WORKS.. My god! finally.
What the hell?

Here is what I had messed up, which you also probably did:

I had too many different python interpreters
Too many different symlinks which I lost track of
almost no package I installed with pip worked without a headache
any attempt to fix using online resources made it worse.

Let's set things right


First, remove all the python packages you installed. I am not sure if this is really necessary, but I did it just so I get a fresh start

pip uninstall -y -r <(pip freeze)

(source: https://stackoverflow.com/a/49200334/2770195)

Also remove pip cache because why not:

~/Library/Caches/pip


Now remove pip

pip uninstall pip


Remove all the third party python installations:
Careful! Don't delete anything under the /System/ folder. Otherwise you WILL have to reinstall macos, it WILL crash, don't do it.

sudo rm -rf /Library/Frameworks/Python.framework
sudo rm -rf "/Applications/Python 2.7"
cd /usr/local/bin/
ls -l /usr/local/bin | grep '../Library/Frameworks/Python.framework/Versions/2.7' | awk '{print $9}' | tr -d @ | xargs rm

(source: https://stackoverflow.com/a/3819829/2770195 but I changed it a bit to remove python3 too)

Remove python path stuff

Edit whatever shell profile you have, like .bash_profile or .zshrc and .zprofile or whichever shell you are using (If you don't know what I'm talking about then it's .bash_profile):

Delete all lines that have Python.framework in it. In other words, delete old paths related to python.

nano .bash_profile

(source: https://stackoverflow.com/a/3819829/2770195 again)

If you have anaconda installed, get rid of that too:

rm -rf ~/anaconda*

(source: https://docs.anaconda.com/anaconda/install/uninstall/)
So far all this was standard. What's important is how you install the new version. Here's the fun part: if you already messed up your python environment,
then there is a good chance you messed up permissions with some packages too. Thus any attempt to install new python versions will seem to work fine for now, but will be a brat later on. That's why the next step is so important:

Fix old package permissions:

sudo chown -R $USER /usr/local/bin/*

Basically, everything in this folder is supposed to NOT require root priviliges, which if they do they give pip a hard time later on. That's why we made everything belong to us
Let's install the one and only python2 we will use!:

(don't worry we will get to python3 as well)

Now that you fixed the permissions, you can go ahead and install a python2 interpreter that will NOT ever require sudo with pip and hence will install your packages just fine:
Here is the trick: We are NOT using easy_install. Got it? No easy_install. It's the devil. brew is love, use brew:

If you don't have brew installed (firstly you should be ashamed of yourself):

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Go to your .profile file again
nano .bash_profile

and add these lines:

⚠ (If you're using macos on arm, add these two lines instead):
export PATH="/usr/local/bin:/usr/local/sbin:$PATH"
export PATH="/opt/homebrew/opt/python@2/libexec/bin:$PATH"


export PATH="/usr/local/bin:/usr/local/sbin:$PATH"
export PATH="/usr/local/opt/python@2/libexec/bin:$PATH"

[UPDATE: crossed python2 installation as it is no longer relevant]

now install python2 using brew:
brew install python@2
(this will also install pip)

(source: https://docs.python-guide.org/starting/install/osx/)
Install python3

brew install python

(this installs latests python, which is right now python3. Also installs pip)
Ok, if you haven't screwed up anything so far, you should be able to use pip with a peace of mind.
I just tried a bunch of packages like numpy and plotly they all worked right away
Golden rule

If you want to maintain the serenity that you have just gained, you have to remember one rule: Never ever use sudo pip install. sudo is the biggest source of confusion with python packages as it screws up the permissions. This is not only true for python, but also nodejs for example, and other environments. There are a lot of posts online that use sudo pip to install packages in their instructions. Always omit the sudo part of that instruction. If you ever accidentally use sudo pip, come back here and apply the steps related to permissions again
gg wp. Now do me a favor and end aging before I die. Just saying. Have fun.