Automate the installation of a Python package (or a cython
        package where the cython components are pre-built).

def install_python_package(self, arch, name=None, env=None, is_dir=True):
        '''Automate the installation of a Python package (or a cython
        package where the cython components are pre-built).'''
        if env is None:
            env = self.get_recipe_env(arch)

        with current_directory(self.get_build_dir(arch.arch)):
            hostpython = sh.Command(self.ctx.hostpython)

            shprint(hostpython, 'setup.py', 'build_ext', '--static-libpq',
                    _env=env)
            shprint(hostpython, 'setup.py', 'install', '-O2',
                    '--root={}'.format(self.ctx.get_python_install_dir()),
                    '--install-lib=.', _env=env)