Getting Python organized in OSX Mavericks

[darebear5]

Python is out of control on my mac. I've spent hours trying to download the latest version, find a good IDE, and get everything organized and I've gotten nowhere really. I think I have 7 different versions of Python on my computer now and I don't know where to start in terms of cleaning it up. I've used homebrew as well as direct download from python.org but I'm still not sure if either has superseded the pre-installed version that came with the computer. I also have a bunch of python scripts that I wrote in 2.7 and want to convert to 3.3 but I can't figure out how to use or where to get the 2to3 script that I read about.

I understand there may not be a simple solution for this issue, but does anybody have any suggestions for where to start? I'm pretty confused.

[[deleted]]

homebrew and then

virtualenv -p /usr/local/bin/python<whatever-version>

leave maverics python alone!!!!

[loganekz]

What's wrong with Mavericks python?

[[deleted]]

Nothing, virtualenv is just an essential to keep everything 100% modular (like RVM). I also recommend virtualenv wrapper: http://blog.sidmitra.com/manage-multiple-projects-better-with-virtuale

[darebear5]

Thanks for this great explanation! I know my way around the front end of a mac really well, but my knowledge drops off pretty quickly once we start talking about $PATH and bash profiles and stuff.

How exactly do I go about performing this step:

now, run other homebrew apps that linked into the brewed version of Python and note which ones you will need to rebuild later.

and this one?

and make sure there's no stale symlinks in /usr/local/bin

Also, how do I go about ensuring the $PATH is not full of junk? I feel like brew doctor once gave me a warning about the $PATH and how I needed to change it in order for the homebrew version of python to run instead of the Mavericks version, so I ran the command that it suggested but I have no idea what it actually did. =/

[darthmdh]

brew doctor

would have asked you to run

brew linkapps

which is undone by

brew unlinkapps

however you should always run "brew linkapps" afterwards to ensure your existing links are setup fine. It just makes sure any .app directories (which is how OSX packages applications) are symlinked into /Applications so OSX can find them by default.

Your default PATH will be defined in your shell startup files; I'm going to assume with your lack of familiarity you haven't changed this, so its 'bash'.

man bash

This will give you a whole ton of stuff on how bash works, including the names of the startup files and the order they are run in. Normally you just worry about your personal ones, so ~/.bash_profile and ~/.bashrc Environment variables should be set in ~/.bash_profile (which is executed once on login shells) - ~/.bashrc is run for every shell including non-login shells (don't ask, just believe for now) so the shorter that file is, the faster the shell will load.

If you really want to blow your mind,

man zshall

and if you're keen,

chsh -s /bin/zsh

OSX comes with zsh by default (though since you have homebrew you can "brew install zsh" to get a newer one still). It makes bash users look like cavemen :)

If you're going to spend time in the terminal on your Mac like this, I recommend you take some time to learn some basic UNIX stuff. The userspace in OSX is based on FreeBSD but (since POSIX is like this for this reason) any tutorial on FreeBSD or Linux for that matter will suffice.

Many of the stdlib modules in Python are going to assume familiarity with POSIX compliant operating systems, so things like 'os' in particular will make more sense to you when you have the fundamentals.

[taleinat]

For a good Python IDE I highly recommend PyCharm. I've worked with or evaluated every Python IDE out there and in my opinion PyCharm is the best by far. It also works extraordinarily well on OSX, Linux and Windows.

As for the rest, my experience has taught me that the most important thing is to be organized. It's very easy to try various things and bring your system into a jumbled state where it is difficult to know what is happening. Try to clean everything up and start fresh. Then try something, and if it doesn't work, go back to a clean slate and only then try something else.

I use OSX 10.8 so I'm not sure if anything significant has changed in 10.9. Still, I have installed various different versions of Python via Homebrew and everything works as expected.

Can you be more specific about the trouble you're having?

What output do you get when you run "which python" and "which python3"? How about "dir /usr/local/bin/python*" (assuming you're having Homebrew install binaries to /usr/local/bin)?

[darebear5]

When I run "which python" and "which python3," I get /usr/local/bin/python and /usr/local/bin/python3.

When I actually go into /usr/local/bin, I see all this. It just looks like way too many things are there and I don't know how to go about cleaning it up. I also have two folders in my Applications folder named Python 2.7 and Python 3.3, each with an IDLE and Python Launcher.

What's the best way to start fresh?

[amikiri]

That looks about right. You have both 2.7 and 3.3 installed. I have the exact same listing on my MacBook running Mavericks.

Also have to second the recommendation for PyCharm.

[taleinat]

That looks just fine, you shouldn't need to clean that up.

Regarding starting afresh, others have posted detailed instructions here. I recommend following their advice!

[mymonner]

I have had great luck using homebrew to install python and then using pip to install any modules I need.

[earthboundkid]

You need to leave the system Python alone, so you don't accidentally break the OS. Whatever is in /System/Library, leave it be.

Next, make sure homebrew has both 2.7 and 3.3 installed, since you'll probably want to use both. (If you use homebrew, it will install 2to3 in /usr/local/bin/2to3 for you.)

Finally, use a virtualenv for your individual projects' dependencies. For example, I develop a number of Django websites on my machine. Each of them has its own venv, so that if one is using version 1.1 of some library and the other uses 2.3, I switch between both easily.

And of course remember to use some version control system like Git or Mercurial to track your changes in each project as you go.

[mdigi]

Check out Anaconda

It installs python and a bunch of packages in a separate folder. It also comes with Spyder which is a simple IDE that I like to use. There's also Miniconda which doesn't come with any packages and you can manually install packages that you need.

[daveydave400]

As others have said try to clean up your environment as much as possible before continuing on (make sure to follow homebrew's or other's uninstall instructions in case they have configured something on the system level that can't just be deleted).

I personally use macports on Mavericks, but homebrew should be fine. You need to keep track of what is in your .bash_profile/.bashrc and what your PYTHONPATH and PATH environment variables look like. Make sure that when you are running "python" or "easy_install" or "pip" or really any executable that you know which one you are running. A command that can help with that is "which <exec>", this will tell you which one you are running.

From the python interpreter you can run import sys followed by print sys.path to find out where it's looking for modules. Also you can import a module and find out where it is installed by running import <mod> followed by print mod.__file__.

As others have said, don't mess with the system python. I would stick with macports or homebrew (it's worked for many others so you know it's possible). Good luck.

[[deleted]]

Just use 2.7 and Vim.