[Python-Dev] Removing PendingDeprecationWarning (original) (raw)

Serhiy Storchaka storchaka at gmail.com
Fri Mar 22 07:49:19 EDT 2019

22.03.19 12:51, Jeroen Demeyer пише:

On 2019-03-22 11:33, Serhiy Storchaka wrote:

What is wrong with PendingDeprecationWarning? It serves the same purpose as DeprecationWarning: it indicates that a feature is planned to be removed in the future. There is no point in having two warnings with exactly the same meaning.

But does not flood the end user with warnings, so you can continue to use deprecated features for a while. This makes the transition more smooth.

What problem do you want to solve at the cost of removing this feature? 1. Typically, a PendingDeprecationWarning is meant to be promoted to a DeprecationWarning in some future release. It takes a minor effort to do that and it may be forgotten. It's just simpler to use DeprecationWarning from the start.

What is wrong if it be forgotten?

Simpler does not mean better.

2. Whenever somebody wants to deprecate something, that person has to decide between the two. That's just more complicated than it needs to be.

If he want to provide a more smooth transition way, he should start with a PendingDeprecationWarning. Otherwise he can use a DeprecationWarning.

And I can easily ask the converse question: what problem do you want to solve by including that feature?

It allowed to mark a feature deprecated for developers without harming the end users.

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