Is it possible to create "placeholders" in an Ibis expression?

[oscaro00]

I want to create "placeholders" in an Ibis expression to show where a group_by, filter, order_by, or limit should appear in a query. However, the values in those methods are not known ahead of time.

It's easy enough to populate the methods with valid columns, but there are cases when a group_by may not receive fields from a user. This poses an issue because the group_by method cannot be left empty. A similar issue occurs with order_by. With filter, I could do filter(True) for an easy work around and set a very large row max in limit.

Is there an easy way to wrap these Ibis table methods to ignore them if no columns are passed to them?

[Sara25776]

Can you give more details on what you are trying to do. Code snippet would me more helpful