英文文档：
eval(expression, globals=None, locals=None)
The arguments are a string and optional globals and locals. If provided, globals must be a dictionary. If provided, localscan be any mapping object.
The expression argument is parsed and evaluated as
英文文档：
eval(expression, globals=None, locals=None)
The arguments are a string and optional globals and locals. If provided, globals must be a dictionary. If provided, localscan be any mapping object.
The expression argument is parsed and evaluated as
