Implementation:Eventual Inc Daft Exceptions

Knowledge Sources	Eventual_Inc_Daft
Domains	Error_Handling, FFI
Last Updated	2026-02-08 14:00 GMT

Overview

Concrete tool for defining the core exception hierarchy used at the Rust-to-Python boundary for classifying and propagating errors.

Description

The exceptions module defines the exception class hierarchy that the Rust engine raises into Python via PyO3. The base class DaftCoreException extends `ValueError`. Below it, DaftTypeError covers type-related errors, and DaftTransientError covers retryable network/IO errors. The transient error branch further specializes into ConnectTimeoutError, ReadTimeoutError, ByteStreamError, SocketError, ThrottleError, and MiscTransientError. These classes are referenced from `src/common/error/src/python.rs` and must not be renamed or deleted without updating the Rust side.

Usage

Catch these exceptions when handling errors from Daft operations. Use `DaftTransientError` and its subclasses to implement retry logic for network-related failures. Use `DaftTypeError` to catch type validation errors from the Rust engine.

Code Reference

Source Location

Repository: Eventual_Inc_Daft
File: daft/exceptions.py
Lines: 1-78

Signature

class DaftCoreException(ValueError):
    """DaftCore Base Exception."""

class DaftTypeError(DaftCoreException):
    """Type Error that occurred in Daft Core."""

class DaftTransientError(DaftCoreException):
    """Daft Transient Error — retryable network/IO errors."""

class ConnectTimeoutError(DaftTransientError):
    """Connection timeout."""

class ReadTimeoutError(DaftTransientError):
    """Read timeout."""

class ByteStreamError(DaftTransientError):
    """Byte stream read error."""

class SocketError(DaftTransientError):
    """Socket error."""

class ThrottleError(DaftTransientError):
    """Throttle/rate-limit error."""

class MiscTransientError(DaftTransientError):
    """Miscellaneous transient error."""

Import

from daft.exceptions import (
    DaftCoreException,
    DaftTypeError,
    DaftTransientError,
    ConnectTimeoutError,
    ReadTimeoutError,
    ThrottleError,
)

I/O Contract

Inputs

Name	Type	Required	Description
(none)	—	—	Exception classes are instantiated by the Rust engine via PyO3

Outputs

Name	Type	Description
Exception instances	DaftCoreException subclasses	Raised into Python when Rust operations fail

Usage Examples

Retry on Transient Errors

import daft
from daft.exceptions import DaftTransientError

for attempt in range(3):
    try:
        df = daft.read_parquet("s3://bucket/data.parquet").collect()
        break
    except DaftTransientError as e:
        print(f"Transient error (attempt {attempt + 1}): {e}")
        if attempt == 2:
            raise

Semantic Links

Page Connections

Double-click a node to navigate. Hold to expand connections.

Principle

Implementation

Heuristic

Environment