The right-shift operator (>>) normally shifts an integer’s binary representation in Python. Airflow overrides it for task objects, turning familiar Python syntax into a readable way to declare workflow dependencies. section 2.2
In a rocket-launch pipeline, downloading launch metadata must finish before fetching pictures, and picture fetching must finish before notification. Writing download_launches >> get_pictures >> notify expresses that ordering directly. section 2.2 section 6.1.1
A linear Airflow dependency chain
download_launches >> get_pictures >> notify Airflow starts each downstream task only after its upstream dependency completes successfully. If download_launches fails, get_pictures is postponed; configurable task retries can address temporary failures such as network problems. section 2.2 section 6.1.1
Listing 6.2 Adding dependencies between tasks
download_launches >> get_pictures #1 get_pictures >> notify download_launches >> get_pictures >> notify #2
Compare separate dependency statements with the equivalent chained expression. section 6.1.1
