ipython complaining about readline

Question

When I install ipython on my osx and run it, I get the following warning:

 /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/  site-packages/IPython/utils/rlineimpl.py:96:  RuntimeWarning: Leopard libedit detected - readline will not be wel  behaved including some crashes on tab completion, and incorrect  history navigation. It is highly recommended that you install  readline, which is easy_installable with: 'easy_install readline' 

I have have installed readline, and do not use the system python that was originally installed in /Library/Frameworks/Python.framework/Versions/2.7/bin/python$. The /usr/bin/python points to version 2.7 as shown below

uname -a Darwin macbook.local 10.8.0 Darwin Kernel Version 10.8.0: Tue Jun  7  16:33:36 PDT 2011; root:xnu-1504.15.3~1/RELEASE_I386 i386  $sudo pip install readline ipython  $ipython --version 0.11  $/usr/bin/python --version #  Python 2.7.1   $which python /Library/Frameworks/Python.framework/Versions/2.7/bin/python 

I have read the question in Python sys.path modification not working - I added /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/readline-6.2.1-py2.7.egg-info to the /Library/Frameworks/Python.framework/Versions/2.7/bin/ipython so that it now looks like this: http://pastebin.com/raw.php?i=dVnxufbS

but I cannot figure out why I am getting the following error:

File "/Library/Frameworks/Python.framework/Versions/2.7/bin/ipython", line 9 sys.path.insert(0,"/Library/Frameworks/Python.framework/Versions/2.7/lib/ python2.7/site-packages/readline-6.2.1-py2.7.egg-info") 

I do not think the above path is an issue, and my goal is to get ipython to working without complaining about readline even though it is installed and imports correctly.

Answer 1

When pip installs readline, it will never be imported, because readline.so goes in site-packages, which ends up behind the libedit System one, located in lib-dynload (OSX Python path order is very odd). easy_install -a readline will actually install usable readline.

So you can either use easy_install, or use pip and muck about with your PYTHONPATH/sys.path (which essentially means: DO NOT USE PIP).

A bit more detail on the IPython list (though there really isn't anything IPython-specific about this issue): http://mail.scipy.org/pipermail/ipython-user/2011-September/008426.html

EDIT: extra note about virtualenv.

There is a bug in virtualenv < 1.8.3, where readline would not be properly staged when you create an env.

Answer 2

If you don't mind mucking around with your PYTHONPATH, here's how you can get rid of that pesky warning:

# move site-packages to the front of your sys.path import sys for i in range(len(sys.path)):     if sys.path[i].endswith('site-packages'):         path = sys.path.pop(i)         sys.path.insert(0, path)         break 

If you're using Django, you can put this in the ipython method of your site-packages/django/core/management/commands/shell.py so that it runs when you run ./manage.py shell.