pathwaycom/pathway · error · ValueError

Table.interpolate(): Invalid column reference for the parame

Error message

Table.interpolate(): Invalid column reference for the parameter timestamp, found a string. Did you mean this.{timestamp} instead of {repr(timestamp)}?

What it means

Error "Table.interpolate(): Invalid column reference for the parameter timestamp, found a string. Did you mean this.{timestamp} instead of {repr(timestamp)}?" thrown in pathwaycom/pathway.

Source

Thrown at python/pathway/stdlib/statistical/_interpolate.py:113

    timestamp | values_a | values_b
    1         | 1.0      | 10.0
    2         | 2.0      | 20.0
    3         | 3.0      | 30.0
    4         | 4.0      | 40.0
    5         | 5.0      | 50.0
    6         | 6.0      | 60.0
    """

    if mode != InterpolateMode.LINEAR:
        raise ValueError(
            """interpolate: Invalid mode. Only Interpolate.LINEAR is currently available."""
        )

    if isinstance(timestamp, pw.ColumnReference):
        timestamp = self[timestamp]
    else:
        if isinstance(timestamp, str):
            raise ValueError(
                "Table.interpolate(): Invalid column reference for the parameter timestamp,"
                + f" found a string. Did you mean this.{timestamp} instead of {repr(timestamp)}?"
            )
        raise ValueError(
            "Table.interpolate(): Invalid column reference for the parameter timestamp."
        )

    ordered_table = self.sort(key=timestamp)

    table = self

    for value in values:
        if isinstance(value, pw.ColumnReference):
            value = self[value]
        else:
            if isinstance(value, str):
                raise ValueError(
                    "Table.interpolate(): Invalid column reference for the parameter value,"

View on GitHub (pinned to fa2f74a464)

Solutions

1. Pass a ColumnReference for the timestamp parameter, e.g. this.timestamp instead of the string 'timestamp'.

Example fix

t.interpolate(this.timestamp, this.value)

When it happens

Trigger: Thrown at python/pathway/stdlib/statistical/_interpolate.py:113 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pathwaycom/pathway@fa2f74a464 (2026-08-15). Data as JSON: /api/errors/d089653fc9fbd56d. Report an issue: GitHub.