asking for alternate method apart from eval in python

Question

Problem i am solving: i am giving liberty to user to make conditions and actions for making rules while inserting data into a database and evaluate these conditions and action, i could not think anything else from using eval , an example of datastructure i created for such purpose is

action_var = ""
a_hash = {"condition":a_condition,
          "action":a_hash}
a_condition ={"param":"abc",
              "operator":">",
              "value":"cde"}
a_action = {"param":action_var,
            "operation":"=",
            "value":"action

So my plan is to take condition id from user and action id from user and then use eval to evaluate the expression .

Help: Am i going in right direction, is there alternate method to do this ?

P.S: I can't use triggers on database, I am kind of using orm wrapper for lmdb. So i use write command at base level.

Edit: i want to have multiple conditions, with and/or mixed, with brackets.

Thanks

@ChristianStrempfer i want to have multiple conditions, with and/or mixed, with brackets. that alternative you provided only operates on two parameters — igauravsehrawat
– igauravsehrawat, Commented Mar 11, 2015 at 11:07
The linked questions doesn't ask about two parameters, neither does the second answer. Feel free to put a bounty on it, if the answers aren't good enough. — Christian Strempfer
– Christian Strempfer, Commented Mar 11, 2015 at 11:30

Dan D. · Accepted Answer · 2015-03-11 07:23:41Z

2

You don't need to use eval. Map those operators to functions and then apply the functions to the arguments. Consider:

>>> import operator
>>> operators = {}
>>> operators['>'] = operator.gt
>>> operators['>'](*[1, 2])
False
>>> 1 > 2
False

answered Mar 11, 2015 at 7:23

Dan D.

75k15 gold badges111 silver badges129 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

igauravsehrawat Over a year ago

thanks, but one problem with it, i want to have multiple conditions, with and/or mixed, with brackets. how will i achieve that ?

Collectives™ on Stack Overflow

asking for alternate method apart from eval in python

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related