i am trying to install pygtk on my mac which then asked me to install pygobject which then asked me to get gobject-introspection . the problem i have in this installation is while configuring it shows this error :

checking for FFI... no
  checking for ffi.h... configure: error: ffi.h not found

please do help me with this as i need to get gtk . 
/usr/include/ffi->location of ffi.h
thanks in advance
ffi.h is provided by the package libffi-dev, which is actually from the gcc source package. and most probably it's available for linux.
problem with configuring gobject-introspection for pygobject and pygtk