Any automatic help to generate extra Require dependencies?

[José Abílio Matos]

Hi,
    my case study is nikola (a static pages generator).

I am using the automatically generated dependencies but that only covers the 
Requires part of the spec file.

My question is if there are any tools that people use, working from the setup 
file, to generate the addition fields like the BuildRequires.

In the installation instructions it says:
"""
Installation Instructions

Assuming you have pip installed:

pip install Nikola

For optional features:

pip install "Nikola[extras]"

For tests:

pip install "Nikola[extras,tests]"
"""

AFAIU the automatic generated dependencies take care of the first step. Is 
there any way, automatic or not, to generate the equivalent of
pip install "Nikola[extras]"?

Best regards,