[Python-ideas] PEP 428 - object-oriented filesystem paths

[Joachim König]

On 09/10/2012 16:30, Michele Lacchia wrote:
>
>     >
>     > A reason *not* to use '+' is that it would violate associativity
>     > in some cases, e.g.
>     >
>     >   (path + "foo") + "bar"
>     >
>     > would not be the same as
>     >
>     >   path + ("foo" + "bar")
>     >
>
>
>     I am missing something. Why not?
>
>
> Because the result would be (respectively): /path/foo/bar/ and 
> /path/foobar/.
> In the second example the two strings would be concatenated and only
> then joined to the path.
> This is a very good argument against the + operator!

But why not interpret a path as a tuple (not a list, it's immutable) of 
path segments and have:

     path + ("foo", "bar")

and

     path + ".tar.gz"

behave different (i.e. tuples add segments and strings add to the last 
segment)?

And of course path1 + path2 adds the segments together.

Joachim

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