Allow schema_extra to be a callable

[selimb]

Change Summary

Allow Config.schema_extra to be a callable so that the generated schema can be post-processed.
Also includes some fixes to the dev scripts for Windows development (I'm on Windows with cmder). Those can be moved to another PR if needed.

Related issue number

fix #889, fix #1051

Checklist

• Unit tests for the changes exist
• Tests pass on CI and coverage remains at 100%
• Documentation reflects the changes where applicable
• changes/1054-selimb.md file added describing change
  (see changes/README.md for details)

[selimb]

Was going to include functions for schema_extra to address both #889 and #1051, but it proved less trivial than I thought to handle all cases.

Could take a stab at it in another PR if you think it'd be useful?

[codecov]

Codecov Report

Merging #1054 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #1054   +/-   ##
======================================
  Coverage     100%    100%           
======================================
  Files          20      20           
  Lines        3349    3352    +3     
  Branches      661     662    +1     
======================================
+ Hits         3349    3352    +3

Impacted Files	Coverage Δ
pydantic/schema.py	100% <100%> (ø)	⬆️

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[samuelcolvin]

otherwise LGTM.

[samuelcolvin]

Was going to include functions for schema_extra to address both #889 and #1051, but it proved less trivial than I thought to handle all cases.

Could take a stab at it in another PR if you think it'd be useful?

Humm, thanks but I think it get's complicated if we start providing functions for these cases within pydantic, there are hundreds of different changes that people might want. I think best to leave things like this up to package users.

[selimb]

Thanks! Believe the comments have been addressed.

Humm, thanks but I think it get's complicated if we start providing functions for these cases within pydantic, there are hundreds of different changes that people might want. I think best to leave things like this up to package users.

Agreed. Sounds good.

[samuelcolvin]

great, thank you.

[selimb]

Thanks to you! Cheers.