[Pyparsing] setResultsName() not working as expected

[cathal c. <cof...@gm...>]

Guys,

I have the following but I don't like it because I am basically repeating
code just to change the results name depending on the situation.

field = '$' + Combine(Word(alphanums)).setResultsName('field_name')
as_field = '$' + Combine(Word(alphanums)).setResultsName('new_field_name')

I would much prefer to do something like this.

field = '$'.suppress() + Combine(Word(alphanums))
as_field = field.copy()
field.setResultsName('field_name')
as_field.setResultsName('new_field_name')

The second however doesn't parse as expected. Why aren't the two of these
equivalent?

Kind regards,
Cathal