Such function accepts only 3 positional arguments, and everything after * can only be passed as keyword arguments.
In Python 3 it is possible to use *l on the left side of an assignment ( Extended Iterable Unpacking), though it gives a list instead of a tuple in this context: first, *rest = Īlso Python 3 adds new semantic (refer PEP 3102): def func(arg1, arg2, arg3, *, kwarg1, kwarg2): It is also possible to use this the other way around: def foo(a, b, c):Īnother usage of the *l idiom is to unpack argument lists when calling a function. def bar(**kwargs):īoth idioms can be mixed with normal arguments to allow a set of fixed and some variable arguments: def foo(kind, *args, **kwargs): Keyword arguments except for those corresponding to a formal parameter as a dictionary. The *args will give you all function parameters as a tuple: def foo(*args): The *args and **kwargs is a common idiom to allow arbitrary number of arguments to functions as described in the section more on defining functions in the Python documentation. This workaround makes my DAG run as I want it to, but I'd still prefer a solution without some hacky workaround. If there is a failure upstream, dumm圓 and dummy4 get skipped and dummy5 gets marked as 'upstream_failed' and the DAG is marked as failed. Now dumm圓 and dummy4 run if there is no upstream failure, dummy5 'runs' if the day is not saturday and gets skipped if the day is saturday, which means the DAG is marked as success in both cases.
AIRFLOW PYTHON BRANCH OPERATOR CODE
My test code looks like this: from datetime import datetime, dateįrom _operator import BranchPythonOperator, PythonOperatorįrom _operator import DummyOperatorīranch_on_saturday = BranchPythonOperator(ĭummy1 > branch_on_saturday > dummy2 > dumm圓īranch_on_saturday > not_saturday > dumm圓ĭummy4 represents a task that I actually need to run, dummy5 is just a dummy.ĭumm圓 still has the trigger rule 'one_success'. I also tried 'all_done' as the trigger rule, then it works correctly if nothing fails, but if something fails dumm圓 still gets executed. I tried using 'all_success' as the trigger rule, then it works correctly if something fails the whole workflow fails, but if nothing fails dumm圓 gets skipped. The BranchPythonOperator and the branches correctly have the state 'upstream_failed', but the task joining the branches becomes 'skipped', therefore the whole workflow shows 'success'. The problem I encountered is when something upstream of the BranchPythonOperator fails: Here I set the trigger rule for dumm圓 to 'one_success' and everything works fine. After that, I join both branches and want to run other tasks. Therefore I used a BranchPythonOperator to branch between the tasks for Saturdays and a DummyTask. In my DAG, I have some tasks that should only be run on Saturdays.
0 kommentar(er)
