Modernize the specfile

- Use %bcond, which can be overridden when building manually
- Don't use obsolete features: %{py3dir}, clearing buildroot,
  %defattr
- Use proper macros for %{__python2}, %{python2_sitelib}

python-mako.spec

@@ -1,5 +1,7 @@
 %if 0%{?fedora} || 0%{?rhel} >= 8
-%global with_python3 1
+%bcond_without python3
+%else
+%bcond_with python3
 %endif
 
 %if 0%{?rhel} > 7
@@ -33,7 +35,7 @@ BuildRequires: python2-nose
 BuildRequires: python2-mock
 %endif #{with python2}
 
-%if 0%{?with_python3}
+%if %{with python3}
 BuildRequires: python3-devel
 BuildRequires: python3-pytest
 BuildRequires: python3-setuptools
@@ -41,7 +43,7 @@ BuildRequires: python3-markupsafe
 BuildRequires: python3-beaker
 BuildRequires: python3-mock
 BuildRequires: python3-nose
-%endif # if with_python3
+%endif #{with python3}
 
 %global _description\
 Mako is a template library written in Python. It provides a familiar, non-XML\
@@ -87,7 +89,7 @@ calling and scoping semantics.
 This package contains documentation in text and HTML formats.
 
 
-%if 0%{?with_python3}
+%if %{with python3}
 %package -n python3-mako
 Summary: Mako template library for Python 3
 Group: Development/Languages
@@ -113,70 +115,47 @@ and flexible models available, while also maintaining close ties to Python
 calling and scoping semantics.
 
 This package contains the mako module built for use with python3.
-%endif # with_python3
+%endif #{with python3}
 
 %prep
 %autosetup -n zzzeek-mako-8e83c7561e3c
 
-%if 0%{?with_python3}
-rm -rf %{py3dir}
-cp -a . %{py3dir}
-%endif # with_python3
-
 %build
-%if %{with python2}
-%{__python} setup.py build
-%endif %{with python2}
-
-%if 0%{?with_python3}
-pushd %{py3dir}
-%{__python3} setup.py build
-popd
-%endif # with_python3
+%{?with_python2:%py2_build}
+%{?with_python3:%py3_build}
 
 
 %install
-rm -rf %{buildroot}
+%{?with_python3:%py3_install}
 
-%if 0%{?with_python3}
-pushd %{py3dir}
-%{__python3} setup.py install --skip-build --root %{buildroot}
 %if %{with python2}
 mv %{buildroot}/%{_bindir}/mako-render %{buildroot}/%{_bindir}/python3-mako-render
 %endif
-popd
-%endif # with_python3
 
-%if %{with python2}
-%{__python} setup.py install --skip-build --root %{buildroot}
-%endif #{with python2}
+%{?with_python2:%py2_install}
 
 # These are supporting files for building the docs.  No need to ship
 rm -rf doc/build
 
 %check
 %if %{with python2}
-python2 setup.py test
+%{__python2} setup.py test
 %endif #{with python2}
 
-%if 0%{?with_python3}
-pushd %{py3dir}
-python3 setup.py test
-popd
+%if %{with python3}
+%{__python3} setup.py test
 %endif
 
 %if %{with python2}
 %files -n python2-mako
-%defattr(-,root,root,-)
 %license LICENSE
 %doc CHANGES README.rst examples
 %{_bindir}/mako-render
-%{python_sitelib}/*
+%{python2_sitelib}/*
 %endif %{with python2}
 
-%if 0%{?with_python3}
+%if 0%{with python3}
 %files -n python3-mako
-%defattr(-,root,root,-)
 %license LICENSE
 %doc CHANGES README.rst examples
 %if %{with python2}
@@ -196,6 +175,7 @@ popd
 - Make python-beaker an optional dependency
 - Add missing python_provide for python3-mako
 - Conditionalize the Python 2 subpackage
+- Modernize the specfile
 
 * Mon Feb 12 2018 Iryna Shcherbina <ishcherb@redhat.com> - 1.0.6-8
 - Update Python 2 dependency declarations to new packaging standards