[Python-Dev] PEP 565: show DeprecationWarning in main (round 2) (original) (raw)

Serhiy Storchaka storchaka at gmail.com
Tue Nov 28 02:54:07 EST 2017

25.11.17 07:33, Nick Coghlan пише:

* FutureWarning: always reported by default. The intended audience is users of applications written in Python, rather than other Python developers (e.g. warning about use of a deprecated setting in a configuration file format).

Given its presence in the standard library since Python 2.3, FutureWarning would then also have a secondary use case for libraries and frameworks that support multiple Python versions: as a more reliably visible alternative to DeprecationWarning in Python 2.7 and versions of Python 3.x prior to 3.7.

I think it is worth to say more explicitly that the primary purpose of FutureWarning (warn about future behavior changes that will not be errors) is kept. It is just added a secondary purpose: a replacement for DeprecationWarning if you want to be sure that it is visible to end users.

I think that showing DeprecationWarning in main.py is just a first step. In future we can extend the scope of showing DeprecationWarning.

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