def python_implementation():
        """Return a string identifying the Python implementation."""
        if 'PyPy' in sys.version:
            return 'PyPy'
        if os.name == 'java':
            return 'Jython'
        if sys.version.startswith('IronPython'):
            return 'IronPython'
        return 'CPython'
Return a string identifying the Python implementation.
stackoverflow/venv/lib/python3.6/site-packages/pip-19.0.3-py3.6.egg/pip/_vendor/distlib/compat.py