Instantiating sub-class from super

[MRAB]

On 2019-10-17 20:06, Eryk Sun wrote:
> On 10/17/19, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>> On Wed, 16 Oct 2019 19:52:50 +0100, MRAB <python at mrabarnett.plus.com>
>> declaimed the following:
>>
>>>Researchers find bug in Python script may have affected hundreds of
>>> studies
>>>https://arstechnica.com/information-technology/2019/10/chemists-discover-cross-platform-python-scripts-not-so-cross-platform/
>>
>> 	That article bugs me...
>>
>> 	As I understand it, the results are affected by the ORDER in which,
>> otherwise independent, file NAMES were returned by the OS.
>>
>> 	Fine: manually ordering the names by some algorithm produces consistent
>> results across various OSs -- but what evidence is there that this file
>> name sort is producing "correct" results? What is the sorting criteria --
>> it is not mentioned in the article. Are the file names time-stamped (in
>> which case a time-ordered sort does make sense)?
> 
> I'm bugged by how the article mis-characterizes the fundamental
> problem. The operating system has nothing to do with the order of a
> directory listing, which varies even with an OS, depending on the file
> system. The latter could store each entry in a tree structure that's
> sorted by filename, or it could use a mapping with hash values, or it
> could simply use the first available slot in a list, based on the
> order of past create and delete operations.
> 
"The operating system has nothing to do with the order of a directory 
listing"?

Well, that depends on the operating system. It might guarantee the order.