Add units to ResultsIndex

[PProfizi]

• Store unit of each result in ResultsIndex.
• Have them appear in the string representation of ResultsIndex, and thus of DataFrame.

We should also think of manipulating UnitSystem objects from PyDPF-Core -> at the Simulation level, to switch UnitSystem.

• Expose a ResultsIndex.units(List[str]) setter? Exposed at the DataFrame level to have DataFrame.units() setter, checking if units are the same and if not, tries to apply a math.unit_convert_fc.

[codecov]

Codecov Report

Merging #330 (3a90a63) into master (7ee22a4) will increase coverage by 0.04%.
The diff coverage is 93.33%.

@@            Coverage Diff             @@
##           master     #330      +/-   ##
==========================================
+ Coverage   82.68%   82.72%   +0.04%     
==========================================
  Files          35       35              
  Lines        3170     3184      +14     
==========================================
+ Hits         2621     2634      +13     
- Misses        549      550       +1     

[germa89]

LGTM! :)

[germa89]

Probably we want to avoid writing "()" if unit is None. :)

And personally, I read better the if before the for. But this is a nit pick :).

Suggested change

	for i, unit in enumerate(units):
	result_values[i] += f" ({unit})" if unit is not None else ""
	if len(units) < len(values):
	units.extend([None] * (len(values) - len(units)))
	else:
	units = [None] * len(values)
	if len(units) < len(values):
	units.extend([None] * (len(values) - len(units)))
	for i, unit in enumerate(units):
	result_values[i] = f" ({unit})" if unit is not None
	else:
	units = [None] * len(values)

[PProfizi]

Probably we want to avoid writing "()" if unit is None. :)

And personally, I read better the if before the for. But this is a nit pick :).

Hi @germa89! Thx for the review! Just to nit pick too, the original line 174 does actually write "" if unit is None ;)

Also, the if after the for is because the operation of adding the unit to the string rep is not needed for None values of units, which is all we are adding in the if.
Thus having the if before the for might be a bit more readable, but is adds unnecessary operations. What I will do is add comments so it is more readable because you are right, it is not really readable.

[germa89]

You might want to use this pytest plugin to automatize "golden" tests

https://github.com/oprypin/pytest-golden#pytest-golden

Feel free to ping me about this.

[PProfizi]

oh nice, thx @germa89, I did not know this plugin!

[PProfizi]

Do you know if it works well for numerical values?