Random Musings of an Insane Mind

Of course, a new upgrade to Python on my devbox and the virtualenv breaks. And, merely reinstalling the virtualenv over top doesn’t work.

This is where you need to make sure your python project has an adequate setup.py to install the dependencies or you’re going to end up reinstalling by hand.

First, deactivate and make sure you’re not in the virtualenv. Get into the virtualenv’s top level directory and:


cd /virtualenvroot
rm -rf bin/ include/ lib/ local/
virtualenv /virtualenvroot
source bin/activate


Then, rerun setup.py with either install or develop and you should be set.

Another update to Python 2.7 and the error:

ImportError: cannot import name MAXREPEAT

occurs when starting an app in the virutalenv.

To fix this, just run:

virtualenv /path/to/existingvirtualenv

    import os, sys, imp, types, tempfile, optparse
  File "/usr/lib/python2.7/tempfile.py", line 34, in 
    from random import Random as _Random
  File "/usr/lib/python2.7/random.py", line 47, in 
    from os import urandom as _urandom
ImportError: cannot import name urandom

You’re using a virtualenv, you’re probably on Debian or Ubuntu, and you upgraded python through apt-get.

To fix it:

virtualenv /path/to/your/virtualenvironment

After the upgrade to Snow Leopard, mysql-python cannot be installed through easy_install.

* Install mysql’s x86_64 version from the .dmg file (I had a problem doing this when booted into the 64bit kernel, a 32bit kernel macbook had no problem) With the 64bit kernel, the system reported ‘no mountable file systems’ when trying to mount the .dmg file. A reboot into 32bit mode allowed the .dmg to be mounted and installed.
* Change into your virtual environment if desired, source bin/activate
* fetch MySQL-python-1.2.3c1

tar xzf MySQL-python-1.2.3c1.tar.gz
cd MySQL-python-1.2.3c1
ARCHFLAGS='-arch x86_64' python setup.py build
ARCHFLAGS='-arch x86_64' python setup.py install

If everything works, you should see:

$ python
Python 2.6.1 (r261:67515, Jul  7 2009, 23:51:51) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
>>>

Some of the possible things you’ll encounter:

After python setup.py build:

ld: warning: in build/temp.macosx-10.6-universal-2.6/_mysql.o, file is not of required architecture
ld: warning: in /usr/local/mysql/lib/libmysqlclient.dylib, file is not of required architecture
ld: warning: in /usr/local/mysql/lib/libmygcc.a, file is not of required architecture
ld: warning: in build/temp.macosx-10.6-universal-2.6/_mysql.o, file is not of required architecture
ld: warning: in /usr/local/mysql/lib/libmysqlclient.dylib, file is not of required architecture
ld: warning: in /usr/local/mysql/lib/libmygcc.a, file is not of required architecture

This means that you have the i386 version of mysql installed. Or, if you have the x86_64 version, you have didn’t include the proper ARCHFLAGS command.

ImportError: dynamic module does not define init function (init_mysql)

this means that the easy_install or the build/install process was run which tried to build a ppc/i386/x86_64 combined build.

If you see messages like:

$ python
Python 2.6.1 (r261:67515, Jul  7 2009, 23:51:51) 
[GCC 4.2.1 (Apple Inc. build 5646)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
/Users/xxxxx/Python/django/lib/python2.6/site-packages/MySQL_python-1.2.3c1-py2.6-macosx-10.6-universal.egg/_mysql.py:3: UserWarning: Module _mysql was already imported from /Users/xxxxx/Python/django/lib/python2.6/site-packages/MySQL_python-1.2.3c1-py2.6-macosx-10.6-universal.egg/_mysql.pyc, but /Users/xxxxx/Python/django/MySQL-python-1.2.3c1 is being added to sys.path
>>> 

Then you are still in the build directory. cd .. and try again.