Use pybuild for building package.

debian/changelog

@@ -3,6 +3,7 @@ python-validictory (0.8.3-4) UNRELEASED; urgency=medium
   * Use debhelper-compat instead of debian/compat.
   * Use Python 3 for building docs.
   * Drop Python 2 support.
+  * Use pybuild for building package.
 
  -- Ondřej Nový <onovy@debian.org>  Fri, 19 Jul 2019 23:56:45 +0200
 

debian/rules

 #!/usr/bin/make -f
 
-DOC_PACKAGE_NAME=python-validictory-doc
-PY2_PACKAGE_NAME=python-validictory
-PY3_PACKAGE_NAME=python3-validictory
-
-PACKAGE_DOCDIR=debian/$(DOC_PACKAGE_NAME)/usr/share/doc/$(DOC_PACKAGE_NAME)
-
-PYVERS  = $(shell pyversions -r)
-PY3VERS = $(shell py3versions -r)
+export PYBUILD_NAME=validictory
 
 %:
-	dh $@ --with python3,sphinxdoc
+	dh $@ --with python3,sphinxdoc --buildsystem=pybuild
 
 override_dh_auto_clean:
 	dh_auto_clean
 	rm -rvf ./docs/build ./*.egg-info ./build
 
 override_dh_auto_build:
-	set -xe; \
-	for py in $(PYVERS) $(PY3VERS); do \
-		$$py setup.py build; \
-	done
+	dh_auto_build
 	make -C docs html
 
-override_dh_auto_install:
-	set -xe; \
-	for py in $(PYVERS); do \
-		$$py setup.py install --skip-build --root debian/$(PY2_PACKAGE_NAME) \
-		--install-layout deb; \
-	done
-	set -xe; \
-		for py in $(PY3VERS); do \
-		$$py setup.py install --skip-build --root debian/$(PY3_PACKAGE_NAME) \
-		--install-layout deb; \
-	done
-	# Remove me when dh_python2 can handle this file
-	rm -vf debian/*/usr/lib/python*/*-packages/*.egg-info/SOURCES.txt
-
 override_dh_installchangelogs:
 	dh_installchangelogs docs/changelog.rst