On 3/10/19 6:25 AM, Barry Scott wrote:
On 2 Oct 2019, at 09:14, DL Neil via Python-list
<python-list@python.org <mailto:python-list@python.org>> wrote:
On 2/10/19 12:52 AM, Rhodri James wrote:
On 01/10/2019 06:03, DL Neil via Python-list wrote:
On 30/09/19 9:28 PM, Barry Scott wrote:
On 30 Sep 2019, at 05:40, DL Neil via Python-list
<python-list@python.org <mailto:python-list@python.org>> wrote:
Should pathlib reflect changes it has made to the file-system?
I think it should not.
The term "concrete" is applied to Path(), PosixPath(), and
WindowsPath() - whereas the others are differentiated with the
prefix "Pure".
I take "concrete" to mean 'existing in reality or real experience'.
Thus, I saw the Pure* entities as supporting abstract paths, but the
concrete entities as representing (and reflecting) real-world (file
system) entities.
Thus, there is no need for .exists() to be available in the Pure
paths, but there is when utilising their concrete implementations.
Sorry but your logic is inconsistent here. For starters, it's not
that there's no need for .exists() in Pure paths, it's that .exists()
is meaningless. Pure paths aren't related to any actual filing
system (to paraphrase you), so existence isn't an option.
However if you insist that "concrete" means "existing in reality",
then .exists() is unnecessary because by your very definition the
path must exist. The very act of creating the Path object would
create the corresponding file or directory. So either pathlib does
something horrific, or your definition is wrong.
Very good! Yes, I'd picked-on .exists() purely (hah!) because it does
not appear in PurePaths, but does in concrete Paths.
On which topic, I went looking for a decent technical definition of
the word, but instead of coming-out smiling, I've been left somewhat
stony-faced (hah, hah!).
"concrete
*
adj.
Of or relating to an actual, specific thing or instance; particular.
"
That said, it is one of the ways that a path can be shown to
transition from some 'pure' state to become 'concrete'.
However, A.N.Other has suggested that I might be mis-applying the word
"concrete", so maybe not.
Concrete means a specific operating system's filesystem rules, Windows
or Posix.
At last the gears have stopped grinding! (cement dust?)
The distinction of "pure", as distinct from "concrete", was readily grasped.
The idea that "concrete" refers to FS rules, cf files on the FS, has
been what so many have been battling to lodge between my ears. Well done!
Also, nicely stated.
In view of my not being the only one to arrive with similar
expectations, do you/we feel that this is carefully and sufficiently
conveyed within the (PSL) documentation?
--
Regards =dn
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