From Fedora Project Wiki
Default Python version macros
For situations when an application (i.e. not a library) is compatible with both Python 3 and Python 2, the default Python version should be used. Depending on Fedora release number the default Python version might differ. For packagers' convenience and better spec readability, the following set of macros is provided:
| Macro | Fedora >= 22 | Fedora <= 21 |
|---|---|---|
| python_default_version | 3 | 2 |
| __python_default | %{__python3} | %{__python2} |
| python_default_sitelib | %{python3_sitelib} | %{python2_sitelib} |
| python_default_sitearch | %{python3_sitearch} | %{python2_sitearch} |
| python_default_devel | python3-devel | python2-devel |
| python_default_prefix | python3- | python- |
| python_default_prefix_only3 | python3- | (empty string) |
Example spec file using this approach:
Name: fooapp
Version: 1.0.0
Release: 1%{?dist}
Summary: This is just an example
License: MIT
URL: http://example.com/
Source0: http://pypi.python.org/packages/source/f/%{name}/%{name}-%{version}.tar.gz
BuildArch: noarch
# This will be python3-devel or python2-devel:
BuildRequires: %{python_default_devel}
# This will be python-setuptools or python3-setuptools
BuildRequires: %{python_default_prefix}setuptools
# This will be python3-pytest or pytest
BuildRequires: %{python_default_prefix_only3}pytest
# Unfortunately with weird package names, we have to do if/else
%if %{python_default_version} > 2
BuildRequires: python3-cairo
Requires: python3-cairo
%else
BuildRequires: pycairo
Requires: pycairo
%endif
%description
This is just an example
%prep
%setup -q
# change the shebangs if neccessary
sed -i 's|#!/usr/bin/env python|#!%{__python_default}|g' *.py
%build
# this will use the default Python interpreter
%{__python_default} setup.py build
%install
# this will use the default Python interpreter
%{__python_default} setup.py install --skip-build --root %{buildroot}
%files
%doc README.rst LICENSE
%{_bindir}/%{name}
# Files will end up in proper locations
%{python_default_sitelib}/%{name}
%{python_default_sitelib}/%{name}-%{version}-py?.?.egg-info
%changelog
...
This package will use Python 3 (or 2) on Fedora releases where Python 3 (or 2) is the default.