[Python-ideas] Change magic strings to enums

[Jacco van Dorp]

I

2018-04-24 15:58 GMT+02:00 Nick Coghlan <ncoghlan at gmail.com>:
> On 24 April 2018 at 22:52, Jacco van Dorp <j.van.dorp at deonet.nl> wrote:
>> Wouldn't it be cleaner to use enums by default instead of those magic
>> strings ? for example, for warnings filter actions, (section 29.5.2),
>> quite near the top of the page.
>
> "It's cleaner" isn't a user problem though. The main justification for
> using enums is that they're easier to interpret in log messages and
> expection tracebacks than opaque constants, and that argument is much
> weaker for well-chosen string constants than it is for other constants
> (like the numeric constants in the socket and errno modules).
>
> For backwards compatibility reasons, we'd want to keep accepting the
> plain string versions anyway (implicitly converting them to their enum
> counterparts).
>
> At a less philosophical level, many of the cases where we use magic
> strings are in code that has to work even when the import system isn't
> working yet - that's relatively straightforward to achieve when the
> code is only relying on strings with particular contents, but *much*
> harder if they're relying on a higher level type like enum objects.
>
> Cheers,
> Nick.


I guess we could add inconsistency as a con, then, since if the import
system isn't working at places where you'd like to use the Enums (or
even executing python code ?). This would mean that to the casual
observer, it'd be arbitrary where they could be used instead.

I wonder how many of these would be in places used by most people,
though. I don't mind putting in some time to figure it out, but I have
no idea where to start. Is there any easily searchable place where I
could scan the standard library for occurences of magic strings ?