espnet3.contract.data.require_fields

source

espnet3.contract.data.require_fields(obj, attr: str) → None

Raise because obj declares no attr.

Every dataset must declare its item fields - as a class attribute, or set on self for one that depends on its own configuration; there is no undeclared fallback.

• Parameters:
  • obj – The class to check, or an instance whose own attributes (set in its __init__) declare a contract its class does not.
  • attr – The attribute name, such as "fields".
• Returns: Nothing; it always raises TypeError.

Examples

>>> class Undeclared:
...     pass
>>> require_fields(Undeclared, "fields")
Traceback (most recent call last):
TypeError: Undeclared does not declare fields; declare `fields` ...