Is there a way to define an assets inputs based on the partition?

Yes, there is a way to define an asset's inputs based on the partition. The documentation provides an example of how to use the

asset_partitions_def_for_input

method within an asset to get the

PartitionsDefinition

for a particular input. This method can be used to log or otherwise act upon the partition information of an input asset within the body of another asset. Here's an example from the documentation:

python from dagster import AssetExecutionContext, DailyPartitionsDefinition, asset  partitions_def = DailyPartitionsDefinition("2023-08-20")  @asset(partitions_def=partitions_def) def upstream_asset():     ...  @asset(partitions_def=partitions_def) def downstream_asset(context: AssetExecutionContext, upstream_asset):     <http://context.log.info|context.log.info>(context.asset_partitions_def_for_input("upstream_asset"))     # materializing the 2023-08-21 partition of this asset will log:     #   DailyPartitionsDefinition("2023-08-20")

In this example, both

upstream_asset

and

downstream_asset

are defined with the same

DailyPartitionsDefinition

. When the

downstream_asset

is materialized, it logs the

PartitionsDefinition

of the

upstream_asset

input, which is determined by the partition key of the run. This approach allows you to define how an asset's inputs should be handled based on the partition information, which can be particularly useful when dealing with partitioned assets and ensuring that the correct partitions are being used as inputs for downstream computations.