Source code for lineapy.exceptions.excepthook

import sys
from types import TracebackType
from typing import Optional, Tuple, Type

from lineapy.exceptions.flag import REWRITE_EXCEPTIONS
from lineapy.exceptions.user_exception import (

ExceptHookArgs = Tuple[Type[Exception], Exception, Optional[TracebackType]]

[docs]def transform_except_hook_args( args: ExceptHookArgs, *changes: TracebackChange ) -> ExceptHookArgs: """ Used by both CLI and Jupyter to pull out the cause from a user exception and also apply the changes to the frames if it's a `UserException`, which is a custom exception that WE created. `changes` is for Jupyter notebook support. They were discovered through trial and error with different type of executions, as seen in ``. If the error is from lineapy, we keep the original frames. """ # the 2nd arg is the Exception (per the docs, and described in # `ExceptHookArgs`) exc_value = args[1] if isinstance(exc_value, UserException): # the user's exception cause = exc_value.__cause__ apply_changes(cause, changes) return type(cause), cause, cause.__traceback__ return args
[docs]def custom_excepthook(*args): """ CLI support. Sets an exception hook, so that if an exception is raised, if it's a user exception, then the traceback will only be the inner cause, not the outer frames. """ return sys.__excepthook__(*transform_except_hook_args(args)) # type: ignore
[docs]def set_custom_excepthook(): """ To support CLI error reporting (or the repl, which we do not currently have). """ if REWRITE_EXCEPTIONS: sys.excepthook = custom_excepthook