cattrs.v Namespace Reference

Functions
str	format_exception (BaseException exc, Union[type, None] type)
List[str]	transform_error (Union[ClassValidationError, IterableValidationError, BaseException] exc, str path="$", Callable[[BaseException, Union[type, None]], str] format_exception=format_exception)

Detailed Description

Cattrs validation.

Function Documentation

format_exception()

str cattrs.v.format_exception	(	BaseException	exc,
		Union[type, None]	type
	)

The default exception formatter, handling the most common exceptions.

The following exceptions are handled specially:

* `KeyErrors` (`required field missing`)
* `ValueErrors` (`invalid value for type, expected <type>` or just `invalid value`)
* `TypeErrors` (`invalid value for type, expected <type>` and a couple special
  cases for iterables)
* `cattrs.ForbiddenExtraKeysError`
* some `AttributeErrors` (special cased for structing mappings)

transform_error()

List[str] cattrs.v.transform_error	(	Union[ClassValidationError, IterableValidationError, BaseException]	exc,
		str	path = "$",
		Callable[ [BaseException, Union[type, None]], str ]	format_exception = format_exception
	)

Transform an exception into a list of error messages.

To get detailed error messages, the exception should be produced by a converter
with `detailed_validation` set.

By default, the error messages are in the form of `{description} @ {path}`.

While traversing the exception and subexceptions, the path is formed:

* by appending `.{field_name}` for fields in classes
* by appending `[{int}]` for indices in iterables, like lists
* by appending `[{str}]` for keys in mappings, like dictionaries

:param exc: The exception to transform into error messages.
:param path: The root path to use.
:param format_exception: A callable to use to transform `Exceptions` into
    string descriptions of errors.

.. versionadded:: 23.1.0