Define %python2 and %python3

See https://pagure.io/packaging-committee/issue/907

Redefine %__pythonX to change the behavior of %pythonX, %pythonX_version, etc.
Use %pythonX in spec.

macros.python-srpm

@@ -2,9 +2,15 @@
 # - they can be used in Build/Requires
 # - they can be used in non-Python packages where requiring pythonX-devel would
 #   be an overkill
+
+# use the underscored macros to redefine the behavior of %%python3_version etc.
 %__python2 /usr/bin/python2
 %__python3 /usr/bin/python3
 
+# use the non-underscored macros to refer to Python in spec, etc.
+%python2 %__python2
+%python3 %__python3
+
 # For backwards compatibility only
 # See the comments in https://src.fedoraproject.org/rpms/python-rpm-macros/pull-request/22
 %__python /usr/bin/python

python-rpm-macros.spec

@@ -1,6 +1,6 @@
 Name:           python-rpm-macros
 Version:        3
-Release:        48%{?dist}
+Release:        49%{?dist}
 Summary:        The unversioned Python RPM macros
 
 # macros: MIT, compileall2.py: PSFv2
@@ -78,6 +78,9 @@ install -m 644 %{SOURCE5} \
 
 
 %changelog
+* Fri Sep 27 2019 Miro Hrončok <mhroncok@redhat.com> - 3-49
+- Define %%python2 and %%python3
+
 * Mon Aug 26 2019 Miro Hrončok <mhroncok@redhat.com> - 3-48
 - Drop --strip-file-prefix option from %%pyX_install_wheel macros, it is not needed