dev-lang/python: Fix epython.py module first install

Fix the issues in obtaining sitedir for epython.py module install when
dev-lang/python is not yet installed.

dev-lang/python/python-3.3.5-r2.ebuild

@@ -286,16 +286,18 @@ src_install() {
 		-i "${ED}etc/conf.d/pydoc-${SLOT}" "${ED}etc/init.d/pydoc-${SLOT}" || die "sed failed"
 
 	# for python-exec
-	python_export python${SLOT} EPYTHON PYTHON
-	export PYTHON_SITEDIR="${EPREFIX}/usr/$(get_libdir)/python${SLOT}/site-packages"
+	local vars=( EPYTHON PYTHON_SITEDIR )
 
 	# if not using a cross-compiler, use the fresh binary
 	if ! tc-is-cross-compiler; then
-		local PYTHON=./python
+		local -x PYTHON=./python
 		local -x LD_LIBRARY_PATH=${LD_LIBRARY_PATH+${LD_LIBRARY_PATH}:}.
+	else
+		vars=( PYTHON "${vars[@]}" )
 	fi
 
-	echo "EPYTHON='${EPYTHON}'" > epython.py
+	python_export "python${PYVER}" "${vars[@]}"
+	echo "EPYTHON='${EPYTHON}'" > epython.py || die
 	python_domodule epython.py
 }