Pip install lxml error

This is the error, under virtualenv or not, that occurred when I tried to install lxml:

/home/virtual/first/build/lxml/src/lxml/includes/etree_defs.h:14:31: fatal error: libxml/xmlversion.h: Fil o directory not found

compilation terminated.

error: command 'gcc' failed with exit status 1

The solution is simple. Before trying to install the package, install:

apt-get install libxml2-dev
apt-get install libxslt1-dev
apt-get install python-devel

Simple, clear and it works very goooooood....