Hollerith constant parsing in pyparsing

hollerith.py

import pyparsing as pp

def hollerith():
    intExpr = pp.Word(pp.nums).setParseAction(lambda t: int(t[0]))
    stringExpr = pp.Forward()

    def countedParseAction(toks):
        n = toks[0]
        contents = pp.CharsNotIn('', exact=n)
        stringExpr << (pp.Suppress(pp.CaselessLiteral('H')) + contents)
        return None

    intExpr.addParseAction(countedParseAction)
    return (pp.Suppress(intExpr) + stringExpr)

Using parsy:

from parsy import generate, regex, string, any_char

@generate
def hollerith():
    num = yield regex(r'[0-9]+').map(int)
    yield string('H')
    return any_char.times(num).concat()