def parse_for_vars(expr, vnames=()):
    root = ast.parse(expr, mode='exec')
    scanner = ExprVarScanner(vnames)
    scanner.visit(root)
    return scanner.varnames
Take internal values and return a string satisfying the tftp
dataset/ETHPy150Open OpenMDAO/OpenMDAO/openmdao/util/string_util.py/parse_for_vars--crossover with--dataset/ETHPy150Open dropbox/emmer/emmer/packets.py/AcknowledgementPacket.pack