This is purely for SEO as this is the actual generic name for this kind of method and it currently does not appear in a Google search for "python constant time compare". Not creating an issue or setting this up for backports as its trivial (I think) and not a functional change.
.. function:: compare_digest(a, b)
Return ``True`` if strings *a* and *b* are equal, otherwise ``False``,
- in such a way as to reduce the risk of
+ using a "constant-time compare" to reduce the risk of
`timing attacks <https://codahale.com/a-lesson-in-timing-attacks/>`_.
See :func:`hmac.compare_digest` for additional details.