concept-expressions.md

title	titleSuffix	description	services	ms.service	ms.subservice	ms.topic	ms.author	author	ms.reviewer	ms.date	ms.custom
SDK and CLI v2 expressions	Azure Machine Learning	SDK and CLI v2 use expressions when a value may not be known when authoring a job or component.	machine-learning	machine-learning	core	conceptual	zhanxia	xiaoharper	larryfr	07/26/2023	cliv2, sdkv2

Expressions in Azure Machine Learning SDK and CLI v2

With Azure Machine Learning SDK and CLI v2, you can use expressions when a value may not be known when you're authoring a job or component. When you submit a job or call a component, the expression is evaluated and the value is substituted.

The format for an expression is ${{ <expression> }}. Some expressions are evaluated on the client, when submitting the job or component. Other expressions are evaluated on the server (the compute where the job or component is running.)

Client expressions

Note

The "client" that evaluates the expression is where the job is submitted or component is ran. For example, your local machine or a compute instance.

Expression	Description	Scope
${{inputs.<input_name>}}	References to an input data asset or model.	Works for all jobs.
${{outputs.<output_name>}}	References to an output data asset or model.	Works for all jobs.
${{search_space.<hyperparameter>}}	References the hyperparameters to use in a sweep job. The hyperparameter values for each trial are selected based on the search_space.	Sweep jobs only.
${{parent.inputs.<input_name>}}	Binds the inputs of a child job (pipeline step) in a pipeline to the inputs of the top-level parent pipeline job.	Pipeline jobs only.
${{parent.outputs.<output_name>}}	Binds the outputs of a child job (pipeline step) in a pipeline to the outputs of the top-level parent pipeline job.	Pipeline jobs only.
${{parent.jobs.<step-name>.inputs.<input-name>}}	Binds to the inputs of another step in the pipeline.	Pipeline jobs only.
${{parent.jobs.<step-name>.outputs.<output-name>}}	Binds to the outputs of another step in the pipeline.	Pipeline jobs only.

Server expressions

[!INCLUDE output-path-expressions]

Next steps

For more information on these expressions, see the following articles and examples:

• CLI v2 core YAML syntax
• Hyperparameter tuning a model
• Tutorial: ML pipelines with Python SDK v2
• Create and run component-based ML pipelines (CLI)
• Example: Iris batch prediction notebook
• Example: Pipeline YAML file