String parsing to initiate Measurement object

[Cs137]

I did not find any information on parsing strings in order to initiate a Measurement object in the pint documentation. The method described for the Quantity object shows an unwanted behaviour and creates a product if ± is used as separator between nominal value and uncertainty. In the case of +/-, a DefinitionSyntaxError is raised.

Example:

import pint

ureg = pint.UnitRegistry()

for item in ['123 g','123 ± 3 g', '123 +/- 3 g']:
    print(ureg(item))

Output:

123 gram
369 gram

---------------------------------------------------------------------------
DefinitionSyntaxError                     Traceback (most recent call last)
Input In [2], in <module>
      3 ureg = pint.UnitRegistry()
      5 for item in ['123 g','123 ± 3 g', '123 +/- 3 g']:
----> 6     print(ureg(item))

...

DefinitionSyntaxError: missing unary operator "/"

I used version 0.20.1 of pint in the example.

[jules-ch]

Closing in favour of #1611.

There is a PR addressing this waiting #1615