how to install lxml python module on mac os 10.5 (leopard)

lxml is an xml library for python that doesn’t suck. It needs a recent libxml2 and libxslt. Mac OS X does not come with recent versions, and 10.5 breaks completely if you force it to try and use a recent version.

I used to use MacPorts for everything (which comes with py25-lxml) but ran into some issues with 10.5. So back to manual installs, it is.

  • assuming your python is the mac os x default…
  • make sure no traces of other pythons in your $PATH
  • download and install libxml2:
       ./configure --prefix=/usr/local/libxml2-2.7.0
       sudo make install
       cd /Library/Python/2.5/site-packages
       sudo ln -s /usr/local/libxml2-2.7.0/lib/python2.5/site-packages/* .
  • download and install libxslt:
       ./configure --prefix=/usr/local/libxslt-1.1.24 --with-libxml-prefix=/usr/local/libxml2-2.7.0 
       sudo make install
       cd /Library/Python/2.5/site-packages
       sudo ln -s /usr/local/libxslt-1.1.24/lib/python2.5/site-packages/* .
  • download and install lxml:
       sudo python install \
         --with-xml2-config=/usr/local/libxml2-2.7.0/bin/xml2-config \

Update March 1, 2009: in order to get libxml2 and libxslt python bindings working on 10.5.6, with a 2.6 version of python, I had to do quite a bit more fiddling. If the above doesn’t work for you, try this:

cd libxml2-2.7.0
./configure --prefix=/usr/local/libxml2-2.7.0
sudo make install
cd ../libxslt-1.1.24
./configure --prefix=/usr/local/libxslt-1.1.24 \
    --with-python \
sudo make install
cd ../libxml2-2.7.0/python

# libxml2 build doesn't support do -arch ppc
export ARCHFLAGS='-arch i386'

# supports libxslt install, sort-of
cp ../../libxslt-1.1.24/python/libxsl* .
cp ../../libxslt-1.1.24/python/
cp ../../libxslt-1.1.24/doc/libxslt-api.xml .

# hack the file to learn the dir structure
curl '' >
python build
sudo python install

And then install lxml normally.

(the use of autoreconf is explained by DarwinPorts folks, the use of ARCHFLAGS is explained by apple, and the hand-editing/hand-merging of libxslt and libxml python bindings for the build based on experimental fiddling.)

Open source product-centric business model

  1. Build a community around a specific free thing.
  2. With that community’s help, design some products that people want, and return the favor by making the products free in raw form (source code).
  3. Let those with more money than time/skill/risk-tolerance buy the more polished version of those products. (That may turn out to be almost everyone)
  4. Do it again and again, building a 40% margin into the products to pay the bills.

(Adapted slightly fromĀ The time/money formula of free).

That pretty much summarizes the business model forĀ sleepycat, MySQL, etc. You could also call it the “provide free lunch for volume, with a fractional but large up-sell” model.