parse_pattern doesn´t parse compound units

[keigezellig]

When using parse_pattern with compound units in the pattern (e.g. 'meter per second'), it won´t parse.

Example:

>>> input = '44 mpsec'
>>> pattern = '{meter per second} mpsec´                 //Tried also 'meter / second' but didn´t work either.
>>> ureg.parse_pattern(input_string=input, pattern=pattern)
>>> []                                                   //Would expect <Quantity(44, 'meter / second')> here 

With a single unit in the pattern (like 'meter') it does work fine

[yerkoescalona]

Hello, this is because you are missing the underscore characters associated with the unit definition

It works with:

>>> input = '44 mpsec'
>>> pattern = '{meter_per_second} mpsec'
>>> ureg.parse_pattern(input_string=input, pattern=pattern)
[44.0 <Unit('meter_per_second')>]

Greetings

[andrewgsavage]

perhaps we should add some regex to parse_pattern so it replaces " per " with " / "?

[keigezellig]

@yerkoescalona Ok, that was not very obvious (i was already looking for the unit definitions in the code, but i couldn´t find them, maybe we could put a description of all unit definitions somewhere in the documentation?)

[andrewgsavage]

At the top of the tutorial

https://pint.readthedocs.io/en/stable/getting/tutorial.html

If no parameters are given to the constructor, the UnitRegistry is populated with the default list of units and prefixes.