[Tutor] Clarification questions about how Python uses references.

[boB Stepp]

On Fri, Jun 25, 2021 at 6:21 PM Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>
> On Fri, 25 Jun 2021 14:48:00 -0500, boB Stepp <robertvstepp at gmail.com>
> declaimed the following:
>
> >The Wikipedia entry on MD5 states, "The MD5 message-digest algorithm
> >is a widely used *hash function* [my emphasis] producing a 128-bit
> >hash value."  Looking up "hash function", the Wikipedia article on it
> >states, "A hash function is any function that can be used to map data
> >of arbitrary size to fixed-size values. The values returned by a hash
> >function are called hash values, hash codes, digests, or simply
> >hashes. The values are usually used to index a fixed-size table called
> >a hash table."  This seems to fit in perfectly well with what Cameron
> >stated and my usage above seems to be correct.  The "index" in this
> >instance would be for the entire file that the MD5 value was computed
> >for.  This may be (ignorant?) quibbling on my part, but it seems that
> >we spend much of our time on these mailing lists trying to be
> >uber-precise in our language usage.  I guess I am either falling into
> >this trap or am engaging in a good thing?  ~(:>))
> >
>
>         But there is no /table/ being indexed by the MD5 hash! So how do you
> locate the original file if given the MD5 hash? File systems that use
> hashes use the file name, and don't hash the file contents (any edit of the
> contents would invalidate the MD5 hash, and require regenerating the hash
> value). The file name stays the same regardless of the edits to the file
> itself, so its hash also stays the same..

I see your point better now; however, the hash function definition
above does say, "...The values are *usually* [my emphasis] used to
index..."  I guess my (ignorant?) quibbling point is that MD5 is still
by definition a hash function.  But this nit is not worth picking.
Everything you say sounds eminently practical and sane!

Cheers!
boB Stepp