<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def __construct_python_version(self):

 """
 Construct a setuptools compatible Python version string.
 
 Constructed based on the environment's reported sys.version_info.
 
 """

        major, minor, micro, release_level, serial = self.sys_version_info
        assert release_level in ("alfa", "beta", "candidate", "final")
        assert release_level != "final" or serial == 0
        parts = [str(major), ".", str(minor), ".", str(micro)]
        if release_level != "final":
            parts.append(release_level[0])
            parts.append(str(serial))
        self.python_version = "".join(parts)