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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def group_re(self):
        ''' Return a regexp pattern with named groups '''
        out = ''
        for token, data in self.tokens():
            if   token == 'TXT':  out += re.escape(data)
            elif token == 'VAR':  out += '(?P<%s>%s)' % (data[1], data[0])
            elif token == 'ANON': out += '(?:%s)' % data
        return out