[path-PEP] Path inherits from basestring again

[Peter Hansen]

Reinhold Birkenfeld wrote:
[on comparing Paths and stings]
> Do you have a use case for the comparison? Paths should be compared only
> with other paths.

I can think of lots, though I don't know that I've used any in my 
existing (somewhat limited) code that uses Path, but they all involve 
cases where I would expect, if comparisons were disallowed, to just wrap 
the string in a Path first, even though to me that seems like it should 
be an unnecessary step:

   if mypath.splitpath()[0] == 'c:/temp':

   if 'tests' in mypath.dirs():

   and lots of other uses which start by treating a Path as a string
   first, such as by doing .endswith('_unit.py')

Any of these could be resolved by ensuring both are Paths, but then I'm 
not sure there's much justification left for using a baseclass of 
basestring in the first place:

   if mypath.splitpath()[0] == Path('c:/temp'):

   if Path('tests') in mypath.dirs():

Question: would this latter one actually work?  Would this check items 
in the list using comparison or identity?  Identity would simply be 
wrong here.

[on removing properties in favour of methods for volatile data]
> My line of thought is that a path may, but does not need to refer to an
> existing, metadata-readable file. For this, I think a property is not
> proper.

Fair enough, though in either case an attempt to access that information 
leads to the same exception.  I can't make a strong argument in favour 
of properties (nor against them, really).

> What about iteration and indexing? Should it support
> "for element in path" or "for char in path" or nothing?

As John Roth suggests, the former seems a much more useful thing to do. 
  The latter is probably as rarely needed as it is with regular strings 
(which I believe is roughly "never" in Python).

[on .read_file_bytes() etc]
> I think it is not exactly bad that these names are somehow outstanding,
> as that demonstrates that something complex and special happens.

Point taken.  What about ditching the "file" part, since it is redundant 
and obvious that a file is in fact what is being accessed.  Thus: 
.read_bytes(), .read_text(), .write_lines() etc.

-Peter