log

Logs the data flowing through the pipeline to the browser console. A no-op layout operator — it passes the data through unchanged — used purely for debugging a .flow() chain.

from gofish import chart, spread, log, stack, rect

chart(seafood).flow(
    spread(by="lake", dir="x"),
    log("after spread"),
    stack(by="species", dir="y"),
).mark(rect(h="count", fill="species"))

Signature

log(prefix=None) -> Operator

Parameters

Debug pass-through: logs each row (optionally under prefix) and forwards it unchanged.

Option	Type	Default	Description
prefix	str		Console prefix string.

Returns an Operator for use inside .flow().

Notes

• Insert log() between operators to inspect the data at that point in the pipeline. Open your browser's developer console to see the output.
• log does not change the data — remove it once you are done debugging.
• To inspect the chart specification itself rather than the data, use .to_ir().