Adding electron_rest_mass unit in physics.units

[1e9abhi1e10]

References to other Issues or PRs

Fixes #24462

Brief description of what is fixed or changed

The electron rest mass (symbol: me) is the mass of a stationary electron, also known as the invariant mass of the electron. It is one of the fundamental constants of physics.

Other comments

Release Notes

• physics.units
  • Added electron rest mass unit

[sympy-bot]

✅

Hi, I am the SymPy bot (v169). I'm here to help you write a release notes entry. Please read the guide on how to write release notes.

Your release notes are in good order.

Here is what the release notes will look like:

• physics.units
  • Added electron rest mass unit (#24463 by @1e9abhi1e10)

This will be added to https://github.com/sympy/sympy/wiki/Release-Notes-for-1.12.

Click here to see the pull request description that was parsed.

<!-- Your title above should be a short description of what
was changed. Do not include the issue number in the title. -->

#### References to other Issues or PRs
<!-- If this pull request fixes an issue, write "Fixes #NNNN" in that exact
format, e.g. "Fixes #1234" (see
https://tinyurl.com/auto-closing for more information). Also, please
write a comment on that issue linking back to this pull request once it is
open. -->
Fixes #24462 


#### Brief description of what is fixed or changed
The electron rest mass (symbol: me) is the mass of a stationary electron, also known as the invariant mass of the electron. It is one of the fundamental constants of physics.


#### Other comments


#### Release Notes

<!-- Write the release notes for this release below between the BEGIN and END
statements. The basic format is a bulleted list with the name of the subpackage
and the release note for this PR. For example:

* solvers
  * Added a new solver for logarithmic equations.

* functions
  * Fixed a bug with log of integers.

or if no release note(s) should be included use:

NO ENTRY

See https://github.com/sympy/sympy/wiki/Writing-Release-Notes for more
information on how to write release notes. The bot will check your release
notes automatically to see if they are formatted correctly. -->

<!-- BEGIN RELEASE NOTES -->
* physics.units
  * Added electron rest mass unit 

<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

[github-actions]

Benchmark results from GitHub Actions

Lower numbers are good, higher numbers are bad. A ratio less than 1
means a speed up and greater than 1 means a slowdown. Green lines
beginning with + are slowdowns (the PR is slower then master or
master is slower than the previous release). Red lines beginning
with - are speedups.

Significantly changed benchmark results (PR vs master)

Significantly changed benchmark results (master vs previous release)

       before           after         ratio
     [41d90958]       [cb037d69]
     <sympy-1.11.1^0>                 
-        1.17±0ms          735±2μs     0.63  solve.TimeSparseSystem.time_linear_eq_to_matrix(10)
-     3.34±0.01ms         1.38±0ms     0.41  solve.TimeSparseSystem.time_linear_eq_to_matrix(20)
-     6.62±0.01ms      2.04±0.08ms     0.31  solve.TimeSparseSystem.time_linear_eq_to_matrix(30)

Full benchmark results can be found as artifacts in GitHub Actions
(click on checks at the top of the PR).

[ThePauliPrinciple]

Looks good to me.

Not directly related to this PR, but it seems inconvenient to add more units. The same (as well as very similar) code needs to be added in different files.

[1e9abhi1e10]

Looks good to me.

Not directly related to this PR, but it seems inconvenient to add more units. The same (as well as very similar) code needs to be added in different files.

I also added an angstrom unit via #24425, what can I do with that
Should I close that one ?

[ThePauliPrinciple]

Maybe it's a good idea to investigate which "common" units SymPy is missing and add them in the same PR.

It would also be helpful if you can squash commits that are just typos. If you're not familiar with squashing in git, then make sure you make a hard backup (you're overriding the version control, so you can't rely on git to back up what you have done).

[sylee957]

There should be a release note for this

[1e9abhi1e10]

There should be a release note for this

Done!