Move f-string compilation of the expression earlier, before the conversion character and format_spec are checked. This allows for error messages that more closely match what a user would expect.

Some were missing and notes were not correct.

Some of the details of comparing mixed types were incorrect or ambiguous.
NotImplemented is only relevant at a lower level than the Expressions
chapter. Added details of comparing range() objects, and default behaviour
and consistency suggestions for user-defined classes. Patch from Andy Maier.

so it is not triggered on import.  The problem is creation of a now-unused
instance "helpDialog = HelpDialog()", left for back compatibility.
So instead trigger the warning when that instance or another is used.

This restores the ability to write encoding names in uppercase like "UTF-8",
which worked in Python 2.

Patch by Mark Roseman.

Issue #19143: platform module now reads Windows version from kernel32.dll to avoid compatibility shims.

Issue #19143: platform module now reads Windows version from kernel32.dll to avoid compatibility shims.

Issue #19143: platform module now reads Windows version from kernel32.dll to avoid compatibility shims.