Expression value column widget problem

[EricTsuei]

I have try both of these code. both can't work.
from pyasm.biz import ExpressionParser
parser = ExpressionParser()
parser.eval(value, env_sobjects=env_sobjects, use_cache=False)

from pyasm.biz import ExpressionParser
parser = ExpressionParser()
value = parser.eval(value, env_sobjects=env_sobjects, use_cache=False)