JoinOnColumn

JoinOnColumn joins upstream tables using a shared key column. It wraps pandas.DataFrame.merge for BioImageFlow workflow graphs.

Inputs are join_column, how, and suffixes. how may be inner, left, right, or outer. Duplicate non-key columns are suffixed.

Use this tool for metadata, sample, or image identifier joins. It fails with pandas merge errors when the join column is missing or when incompatible merge arguments are provided.

Dependencies and Core Libraries

BioImageFlow DataFrameTool merge APIs and pandas.

Assumptions

Every upstream table contains the named join column.

Minimal Example

from bioimageflow_common_tools import JoinOnColumn

joined = JoinOnColumn()(measurements, metadata, join_column="sample_id")

Expected Results

The output contains the configured pandas merge result and one copy of the join column.

Failure Modes

Missing join columns, invalid how values, or duplicate-key semantics that are not intended fail or expand rows through pandas merge behavior.