chroma-core/chroma · error · TypeError

select must be a Select object, dict, list, set, or None, go

Error message

select must be a Select object, dict, list, set, or None, got {type(select).__name__}

What it means

Error "select must be a Select object, dict, list, set, or None, got {type(select).__name__}" thrown in chroma-core/chroma.

Source

Thrown at chromadb/execution/expression/plan.py:155

        elif isinstance(limit, dict):
            self._limit = Limit.from_dict(limit)
        else:
            raise TypeError(
                f"limit must be a Limit object, dict, int, or None, got {type(limit).__name__}"
            )

        # Handle select parameter
        if select is None:
            self._select = Select()
        elif isinstance(select, Select):
            self._select = select
        elif isinstance(select, dict):
            self._select = Select.from_dict(select)
        elif isinstance(select, (list, set)):
            # Convert list/set of strings to Select object
            self._select = Select.from_dict({"keys": list(select)})
        else:
            raise TypeError(
                f"select must be a Select object, dict, list, set, or None, got {type(select).__name__}"
            )

    def to_dict(self) -> Dict[str, Any]:
        """Return a JSON-serializable dictionary representation."""
        return {
            "filter": self._where.to_dict() if self._where is not None else None,
            "rank": self._rank.to_dict() if self._rank is not None else None,
            "group_by": self._group_by.to_dict(),
            "limit": self._limit.to_dict(),
            "select": self._select.to_dict(),
        }

    # Builder methods for chaining
    def select_all(self) -> "Search":
        """Select all predefined keys (document, embedding, metadata, score)."""
        new_select = Select(keys={Key.DOCUMENT, Key.EMBEDDING, Key.METADATA, Key.SCORE})
        return Search(

View on GitHub (pinned to aecdd12c8a)

When it happens

Trigger: Thrown at chromadb/execution/expression/plan.py:155 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of chroma-core/chroma@aecdd12c8a (2026-08-16). Data as JSON: /api/errors/0a8d01083df584a7. Report an issue: GitHub.