'Return all available keyword names beginning with expr'

def _keywords_from_scope(self, expr, scoperef):

    keyword_completions = []
    keywords = self.langintel.langinfo.keywords
    expr = (expr and expr[:3])
    for name in keywords:
        if ((not expr) or name.startswith(expr)):
            keyword_completions.append(('keyword', name))
    return keyword_completions
