Support scanning a specific branch of a table

[malcolmbovey]

Feature Request / Improvement

As far as I can tell, PyIceberg does not directly support being able to scan a particular branch of an iceberg table. For example, there is no way to be able to run an equivalent of queries like

SELECT * FROM <namespace>.<table>.<branch>;

as documented in https://iceberg.apache.org/docs/1.8.0/branching/#schema-selection-with-branches-and-tags

I can see that PR #941 to add support to write to branches in Pyiceberg is well on its way to be being merged in, so this would be a useful complement.

Alternatively, perhaps I'm mistaken and there is already a way to do this, but it wasn't clear in the documentation

[kevinjqliu]

I dont think we have support for reading directly from a branch name yet. On the read side, you can specify a specific snapshot_id,

iceberg-python/pyiceberg/table/__init__.py

Line 925 in f186d58

snapshot_id: Optional[int] = None,

I think if you find the specific snapshot_id for the branch, you can use the scan API to read.

[malcolmbovey]

Thanks, would you like me to draft a PR tp enable a branch parameter to be passed to table.scan ?

[Fokko]

Hey @malcolmbovey I think that would be a great addition 👍