Error when installing scrapy using pypi

Error when installing scrapy using pypi

I'm on Debian 6 with python 2.7 and I've tried to install scrapy
(according to the doc) using the command:
pip install Scrapy
and got this error
gcc -pthread -fno-strict-aliasing -DNDEBUG -g -fwrapv -O2 -Wall
-Wstrict-prototypes -fPIC -I/usr/include/python2.7 -c
twisted/runner/portmap.c -o
build/temp.linux-x86_64-2.7/twisted/runner/portmap.o
twisted/runner/portmap.c:10:20: error: Python.h: No such file or directory
twisted/runner/portmap.c:14: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '*' token
twisted/runner/portmap.c:31: error: expected '=', ',', ';', 'asm' or
'__attribute__' before '*' token
twisted/runner/portmap.c:45: error: expected '=', ',', ';', 'asm' or
'__attribute__' before 'PortmapMethods'
twisted/runner/portmap.c: In function 'initportmap':
twisted/runner/portmap.c:55: warning: implicit declaration of function
'Py_InitModule'
twisted/runner/portmap.c:55: error: 'PortmapMethods' undeclared (first use
in this function)
twisted/runner/portmap.c:55: error: (Each undeclared identifier is
reported only once
twisted/runner/portmap.c:55: error: for each function it appears in.)
error: command 'gcc' failed with exit status 1
----------------------------------------
Cleaning up...
Command /usr/bin/python -c "import
setuptools;__file__='/tmp/pip_build_root/Twisted/setup.py';exec(compile(open(__file__).read().replace('\r\n',
'\n'), __file__, 'exec'))" install --record
/tmp/pip-FSl8pj-record/install-record.txt
--single-version-externally-managed failed with error code 1 in
/tmp/pip_build_root/Twisted
Storing complete log in /root/.pip/pip.log
I think the problem is when installing Twisted library, so i tried to
install it alone using:
pip install Twisted
and got the same error.
How can I fix this ?