BasPH opened a new issue, #26499:
URL: https://github.com/apache/airflow/issues/26499
### Apache Airflow version
2.4.0
### What happened
When running `zip()` with different-length lists, I get an unexpected result:
```python
from datetime import datetime
from airflow import DAG
from airflow.decorators import task
with DAG(
dag_id="demo_dynamic_task_mapping_zip",
start_date=datetime(2022, 1, 1),
schedule=None,
):
@task
def push_letters():
return ["a", "b", "c"]
@task
def push_numbers():
return [1, 2, 3, 4]
@task
def pull(value):
print(value)
pull.expand(value=push_letters().zip(push_numbers()))
```
Iterates over `[("a", 1), ("b", 2), ("c", 3), ("a", 1)]`, so it iterates for
the length of the longest collection, but restarts iterating elements when
reaching the length of the shortest collection.
I would expect it to behave like Python's builtin `zip` and iterates for the
length of the shortest collection, so 3x in the example above, i.e. `[("a", 1),
("b", 2), ("c", 3)]`.
Additionally, I went digging in the source code and found the `fillvalue`
argument which works as expected:
```python
pull.expand(value=push_letters().zip(push_numbers(), fillvalue="foo"))
```
Iterates over `[("a", 1), ("b", 2), ("c", 3), ("foo", 4)]`.
However, with `fillvalue` not set, I would expect it to iterate only for the
length of the shortest collection.
### What you think should happen instead
I expect `zip()` to iterate over the number of elements of the shortest
collection (without `fillvalue` set).
### How to reproduce
See above.
### Operating System
MacOS
### Versions of Apache Airflow Providers
_No response_
### Deployment
Other
### Deployment details
OSS Airflow
### Anything else
_No response_
### Are you willing to submit PR?
- [ ] Yes I am willing to submit a PR!
### Code of Conduct
- [X] I agree to follow this project's [Code of
Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
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