[Python-ideas] Moving typing out of the stdlib in Python 3.7?

Nick Coghlan ncoghlan at gmail.com
Sat Nov 4 10:05:33 EDT 2017

On 4 November 2017 at 00:35, Guido van Rossum <guido at python.org> wrote:
> [A copy from https://github.com/python/typing/issues/495 to get more
> people's attention to this issue.]
> I'm wondering if we should remove typing from the stdlib. Now's the time to
> think about this, as the feature freeze for 3.7 is about 12 weeks away.
> Cons:
> People have to depend on a PyPI package to use typing (but they do anyway
> for typing_extensions)
> It's a backward incompatibility for users of Python 3.5 and 3.6 (but the
> typing module was always provisional)
> Pros:
> The typing module can evolve much faster outside the stdlib
> We could get rid of typing_extensions (and maybe even mypy_extensions)
> If we don't do this I worry that we're entering a period where many new
> typesystem features end up in typing_extensions and users will be confused
> about which items are in typing and which in typing_extensions (not to
> mention mypy_extensions). Anything new to be added to typing (e.g. Const,
> Final, Literal, or changing ABCs to Protocols) would have to be added to
> typing_extensions instead, and users would be confused about which features
> exist in which module. Moving typing out of the stdlib can make things
> potentially simpler, at the cost of an extra pip install (but they'll need
> one anyway for mypy).
> Thoughts?

Perhaps typing could switch to being a bundled module, such that it
had its own version, independent of the Python standard library
version, but was still present by default in new installations?


Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia

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