License for Python module derived from standard library module

Question

I'm creating a short module, which is directly based on the netrc module in the Python standard library. It's the same module, with some alterations and extensions.

Is my understanding correct that I need to include all the default Python licenses? The PSF one, the BEOPEN one (for Python 2.0), the CNRI one (Python 1.6.1) and the CWI one (versions 0.9.0 to 1.2).
And that the new module is automatically licensed under the standard PSF license? Or is there a way to relicense the module for derivative works, while keeping the old licenses (the four above) with the project?

I used the original module from the Python 3.5.2 source, so I assume it would have to include this exact license version. As seen here: https://docs.python.org/3.5/license.html

Answer 1

Is my understanding correct that I need to include all the default Python licenses? The PSF one, the BEOPEN one (for Python 2.0), the CNRI one (Python 1.6.1) and the CWI one (versions 0.9.0 to 1.2).

Yes. The text is unfortunately a rather monolithic big text. See https://enterprise.dejacode.com/license_library/Demo/python/#license-text

The license states in section 2.:

provided, however, that PSF's  License Agreement and PSF's notice of
copyright, i.e., "Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006
Python Software Foundation; All Rights Reserved" are retained in Python
alone or in any derivative version prepared by Licensee. 

And that the new module is automatically licensed under the standard PSF license?

The PSF "licenses" are a tad on the complicated side so these licenses would apply IMHO and may likely not be "sub-licensable". For instance in section 2. of the BEOPEN sub-section:

however, that the BeOpen Python License is retained in the 
Software, alone or in any derivative version prepared by Licensee. 

Or is there a way to relicense the module for derivative works, while keeping the old licenses (the four above) with the project?

Possibly, though that would not be the right thing to do IMHO: when forking I prefer keeping the original licenses as-is. Based on the text above I would tend to say that you cannot re-license using another license.