Why branching handles conditional logic in Apache Airflow - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a BranchPythonOperator that decides the next task based on a condition.

Apache Airflow

branch_task = BranchPythonOperator(task_id='branching', python_callable=[1], dag=dag)

Drag options to blanks, or click blank then click option'

Abranch_logic

Brun_task

Cchoose_branch

Dstart_branch

Attempts:

3 left

💡 Hint

Common Mistakes

Using a string instead of a function name

Passing a task instead of a callable

The python_callable parameter must be a function that returns the task_id to follow. Here, choose_branch is the function that handles the condition.

2fill in blank

medium

Complete the function to return the correct task_id based on the value of condition.

Apache Airflow

def choose_branch():
    condition = True
    if condition:
        return [1]
    else:
        return 'task_b'

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A'task_a'

B'task_c'

C'branch_task'

D'start_task'

Attempts:

3 left

💡 Hint

Common Mistakes

Returning a variable instead of a string

Missing quotes around the task_id

The function must return the task_id string of the next task to run. If condition is True, it returns 'task_a'.

3fill in blank

hard

Fix the error in the BranchPythonOperator definition by completing the missing parameter.

Apache Airflow

branch_task = BranchPythonOperator(task_id='branching', python_callable=choose_branch, [1]=dag)

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Astart_date

Bschedule_interval

Cdefault_args

Ddag

Attempts:

3 left

💡 Hint

Common Mistakes

Using schedule_interval instead of dag

Omitting the DAG parameter

The dag parameter links the operator to the DAG object. Without it, the task is not part of the DAG.

4fill in blank

hard

Fill both blanks to create a DAG with a BranchPythonOperator and two downstream tasks.

Apache Airflow

with DAG('branching_dag', start_date=days_ago(1), schedule_interval='@daily') as dag:
    branch = BranchPythonOperator(task_id='branch', python_callable=[1])
    task_a = DummyOperator(task_id=[2])
    task_b = DummyOperator(task_id='task_b')
    branch >> [task_a, task_b]

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Achoose_branch

B'task_a'

C'branch_task'

Drun_branch

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching task_id and return value

Wrong function name in callable

The python_callable must be the function choose_branch. The task_a DummyOperator must have the task_id 'task_a' to match the branch return value.

5fill in blank

hard

Fill all three blanks to define a branching function that returns different task_ids based on a variable.

Apache Airflow

def choose_branch():
    value = 10
    if value > [1]:
        return [2]
    else:
        return [3]

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A5

B'task_high'

C'task_low'

D15

Attempts:

3 left

💡 Hint

Common Mistakes

Using numbers instead of strings for task_ids

Wrong comparison operator

The function checks if value is greater than 5. If true, it returns 'task_high', else 'task_low'.