StepSequence Class

Represents a list of steps in a Pipeline and the order in which to execute them.

Use a StepSequence when initializing a pipeline to create a workflow that contains steps to run in a specific order.

Initialize StepSequence.

Inheritance

builtins.object

StepSequence

Constructor

StepSequence(steps=None)

Parameters

steps

list

default value: None

The steps for StepSequence.

steps

list

Required

steps for StepSequence.

Remarks

A StepSequence can be used to easily run steps in a specific order, without needing to specify data dependencies through the use of PipelineData.

An example to build a Pipeline using StepSequence is as follows:

   from azureml.pipeline.core import Pipeline, StepSequence
   from azureml.pipeline.steps import PythonScriptStep

   prepare_step = PythonScriptStep(
       name='prepare data step',
       script_name="prepare_data.py",
       compute_target=compute
   )

   train_step = PythonScriptStep(
       name='train step',
       script_name="train.py",
       compute_target=compute
   )

   step_sequence = StepSequence(steps=[prepare_step, train_step])
   pipeline = Pipeline(workspace=ws, steps=step_sequence)

In this example train_step will only run after prepare_step has successfully completed execution.

To run three steps in parallel and then feed them into a fourth step, do the following:

   initial_steps = [step1, step2, step3]
   all_steps = StepSequence(steps=[initial_steps, step4])
   pipeline = Pipeline(workspace=ws, steps=all_steps)