Is it recommended to use `conditional` inside a ` dynamic` s

Question

Is it recommended to use `conditional` inside a ` dynamic` step or should normal python control flow work there We re seeing a number of issues w failing to bind variables in a dynamic workflow using normal `if` `else` blocks

Samhita Alla · Answer

Tasks within a dynamic workflow return Promise objects I think conditional is a better choice < Kevin Su> is `conditional` supported within dynamic workflows

Kevin Su · Answer

Yes it should work

Rahul Mehta · Answer

Thanks I ll give that a try

Rahul Mehta · Answer

Something feels strange here I m getting the following error w the below construct in a ` dynamic` step `regress` is a boolean ``` Logical and or is not operations are not supported Expressions Comparison lt lt = gt gt = == = or Conjunction amp | are supported Received an evaluated expression with val False in train estimator if ``` ``` flytekit conditional train estimator if regress then estimator train regressor else then estimator train classifier ```

Rahul Mehta · Answer

Seems odd that I can t directly pass a boolean value into `flytekit conditional` I also tried `regress == True` as well and that resulted in the same error

Rahul Mehta · Answer

I guess I could push all of this into the task but then that unfortunately forces us to create a second task for training the estimator vs re using an existing task

Kevin Su · Answer

Below is the workflow I ran in flyte cluster it works for me However it doesn t work in local execution now ```from flytekit import workflow task dynamic conditional task def t1 gt bool return True task def t2 gt bool return False dynamic def d1 gt bool a = t1 return conditional train estimator if a==True then t2 else then t2 workflow def wf gt bool return d1 if name == main print wf ```

Rahul Mehta · Answer

< Kevin Su> does this work if `a` is an arg to `d1` vs the result of a task

Kevin Su · Answer

btw should use `regress == True` instead of `regress` Otherwise it will fail

Kevin Su · Answer

gt does this work if `a` is an arg to `d1` vs the result of a task let me try it

Kevin Su · Answer

it doesn t work because the type of `a` is bool instead of promise

Kevin Su · Answer

tl dr `a` in the if statement must be a promise

Rahul Mehta · Answer

Hm ok Is there a way to do something like `Promise of my literal ` kind of abusing JavaScript notation here but you get the point

Rahul Mehta · Answer

Or maybe another way is there a reason preventing this from working w both promises and literals

Kevin Su · Answer

gt Hm ok Is there a way to do something like `Promise of my literal ` kind of abusing JavaScript notation here but you get the point we don t have that now but you could add a task to convert it to a promise in dynamic ``` task def convert to promise a bool gt bool return a``` gt Or maybe another way is there a reason preventing this from working w both promises and literals I think we can support pure python type in ` if` as well we can try to update it in the next release For now to work around this issue just create a task to convert it to a promise sorry

Kevin Su · Answer

cc < Yee> < Eduardo Apolinario eapolinario > do we have another way to handle `bool` or `int` in ` if` in `condition` currently we can only use promise in condition

Rahul Mehta · Answer

Thanks < Kevin Su> I d be happy to contribute this too if there are other milestones you guys are working towards for the next release

Kevin Su · Answer

yeah I just created an <https github com flyteorg flyte issues 2999|issue> for it feel free to create a pr thanks