python pandas installation issues

Question

I have tried installing from

1. source (python setup.py install into the extracted tar ball dir)
2. using pip
3. using easy_install but nothing seems to work...I have downloaded and upgraded xcode, installed command-line tools..

I cloned the github repository for pandas

cd ../pandas
python setup.py install 
running install
running bdist_egg
running egg_info
writing requirements to pandas.egg-info/requires.txt
writing pandas.egg-info/PKG-INFO
writing top-level names to pandas.egg-info/top_level.txt
writing dependency_links to pandas.egg-info/dependency_links.txt
reading manifest file 'pandas.egg-info/SOURCES.txt'
reading manifest template 'MANIFEST.in'
warning: no files found matching 'setupegg.py'
no previously-included directories found matching 'doc/build'
warning: no previously-included files matching '*.so' found anywhere in distribution
warning: no previously-included files matching '*.pyd' found anywhere in distribution
warning: no previously-included files matching '*.pyc' found anywhere in distribution
warning: no previously-included files matching '.DS_Store' found anywhere in distribution
writing manifest file 'pandas.egg-info/SOURCES.txt'
installing library code to build/bdist.macosx-10.6-intel/egg
running install_lib
running build_py
copying pandas/version.py -> build/lib.macosx-10.6-intel-2.7/pandas
running build_ext
**gcc-4.2 not found, using clang instead**
building 'pandas.index' extension
clang -fno-strict-aliasing -fno-common -dynamic -arch i386 -arch x86_64 -g -O2 -DNDEBUG -g -O3 -I/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/core/include -Ipandas/src/klib -Ipandas/src -I/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 -c pandas/index.c -o build/temp.macosx-10.6-intel-2.7/pandas/index.o
In file included from pandas/index.c:260:
In file included from pandas/src/klib/khash_python.h:3:
pandas/src/klib/khash.h:573:1: warning: expression result unused [-Wunused-value]
KHASH_MAP_INIT_STR(str, size_t)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
pandas/src/klib/khash.h:565:2: note: expanded from macro 'KHASH_MAP_INIT_STR'
    KHASH_INIT(name, kh_cstr_t, khval_t, 1, kh_str_hash_func, kh_str_hash_equal)
    ^

---more output like that...and in the end

Installed /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-      packages/pandas-0.10.1.dev_c934e02-py2.7-macosx-10.6-intel.egg
Processing dependencies for pandas==0.10.1.dev-c934e02
Searching for pytz
Reading http://pypi.python.org/simple/pytz/
Reading http://pytz.sourceforge.net
Reading http://sourceforge.net/project/showfiles.php?group_id=79122
Reading http://www.stuartbishop.net/Software/pytz
Reading http://sourceforge.net/projects/pytz/
Best match: pytz 2012h
Downloading http://pypi.python.org/packages/2.7/p/pytz/pytz-2012h-py2.7.egg#md5=4258fcfc023e9ff0057405d935fc6e1d
Processing pytz-2012h-py2.7.egg
creating /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pytz-2012h-py2.7.egg
Extracting pytz-2012h-py2.7.egg to /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
Adding pytz 2012h to easy-install.pth file

Installed /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pytz-2012h-py2.7.egg
-----
Installed /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/six-1.2.0-py2.7.egg
Searching for numpy==1.6.2
Best match: numpy 1.6.2
Adding numpy 1.6.2 to easy-install.pth file

Using /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages
Finished processing dependencies for pandas==0.10.1.dev-c934e02

ipython

Python 2.7.3 (v2.7.3:70274d53c1dd, Apr  9 2012, 20:52:43) 
Type "copyright", "credits" or "license" for more information.

IPython 0.14.dev -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

In [1]: import pandas

seems to work without issues..

when i use easy_install to install pandas, the on-screen output seems to suggest that it worked but on loading, python is not able to find the library

sudo easy_install pandas
Searching for pandas
Best match: pandas 0.10.1.dev-c934e02
Processing pandas-0.10.1.dev_c934e02-py2.7-macosx-10.8-intel.egg
pandas 0.10.1.dev-c934e02 is already the active version in easy-install.pth

Using /usr/local/lib/python2.7/site-packages/pandas-0.10.1.dev_c934e02-py2.7-macosx-10.8-intel.egg
Processing dependencies for pandas
Finished processing dependencies for pandas

dekumar-mn:ipython dekumar$ python
Python 2.7.3 (v2.7.3:70274d53c1dd, Apr  9 2012, 20:52:43) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.

>>> import pandas as pd
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named pandas

Solution

You have multiple versions of Python 2.7. You installed pandas for one version, and then tried to import it into the other, and you can't do that, because they have separate site libraries.

If you need multiple versions of Python 2.7 for some reason, you have to learn how to manage multiple versions of Python. For example, always be sure whether you're using /usr/bin/easy_install or /usr/local/bin/easy_install, and use the one that goes with the python you plan to run.

But you probably don't need multiple versions. If you just uninstall the non-Apple one, everything will be a lot easier.

You can figure out the details from the paths in your logs. The manual install went to /Library/Python/2.7/site-packages, which is where Apple's /usr/bin/python looks. But the easy_install went to /usr/local/lib/python/2.7/site-packages, which is where the third-party (presumably Homebrew, from the brew tag?) /usr/local/bin/python. So clearly, the first python on your path is /usr/bin/python, while the first easy_install is /usr/local/bin/easy_install. That's going to lead to confusion, as it did here.

Even worse, if you install ipython into both Pythons, whichever one you install second is going to end up as /usr/local/bin/ipython, which is going to lead to even more confusion.

If you do sudo /usr/bin/easy_install pandas, you can use pandas in the Apple Python. To make sure that's the one you run, always do /usr/bin/python or /usr/bin/python /usr/local/bin/ipython. If you do sudo /usr/local/bin/easy_install pandas, you can use pandas in the third-party Python. To make sure that's the one you run, always do /usr/local/bin/python or /usr/local/bin/python /usr/local/bin/ipython.

Looking at your comments, and your more detailed edit, it's possible that you actually have two third-party Pythons here, which makes things even more confusing. If both of them prefer /usr/local/bin (and unless you're using MacPorts or Fink, they do), you've probably got one of them half-overwritten by the other, and there's just no way you're going to get this working. If that's the case, I would recommend that you do something radical. If you're not willing to do an install-from-scratch-with-settings-import of OS X, at least rm -rf /usr/local /Library/Python ~/Library/Python, then reinstall brew and any other third-party stuff you need, and this time make sure to only install one extra Python (although zero would still be better!).

Meanwhile, two minor side notes:

1. It's almost always better to use pip than easy_install. If you don't have it, sudo easy_install pip, and now you do. (The only common exceptions to that "almost" are for pip itself, and for readline.)

2. Don't use sudo with Homebrew. Homebrew goes through a lot of trouble to set up all of the directories it touches so you never need sudo. Once you start doing sudo brew, sudo /usr/local/bin/easy_install, etc., you end up breaking that, so later installations get permissions errors, and it takes a lot of work with brew doctor to fix everything.