Creating a Conditional Task

A special type of task that enables conditional execution paths within a workflow. Conditional tasks allow the workflow to choose different execution paths based on the outcome of a previous task or variable.

Conditional task are typically structured with a condition followed by one or more possible execution paths (if-else branches).

Example

This is how the flow will be of the given example workflow

Code

Create file names workflow.py and paste the following contents into the file:

from truefoundry.workflow import task, workflow, PythonTaskConfig, TaskPythonBuild, conditional


task_config = PythonTaskConfig(image=TaskPythonBuild(
        python_version="3.11",
        pip_packages=["truefoundry[workflow]==0.4.8"],
    )
)

@task(task_config=cpu_task_config)
def generate_number() -> int:
    return 7

@task(task_config=cpu_task_config)
def process_low() -> str:
    return "Low number processing"

@task(task_config=cpu_task_config)
def process_high() -> str:
    return "High number processing"

@workflow
def conditional_workflow() -> str:
    number = generate_number()

    result = conditional("branch")\
        .if_(number < 5).then(process_low())\
        .else_().then(process_high())

    return result

Now run the below command in the terminal to deploy your workflow, replace <workfspace-fqn> with the workspace fqn which you can find on the UI.

tfy deploy workflow \
  --name conditional-example-wf \
  --file workflow.py \
  --workspace_fqn "Paste your workspace FQN here"

In this example:

• generate_number: A task that generates a number.
• process_low and process_high: Tasks that process the number based on whether it is low or high.
• conditional: A branch node that checks if the number is less than 5. If true, it executes process_low, otherwise it executes process_high.

Conditional task on ui

• When you see the graph of a workflow containing the conditional task then you can see that the green box here represents the conditional task and the green color indicates that the task execution was successful.