predictably.validate.is_sequence_named_objects#

predictably.validate.is_sequence_named_objects(seq_to_check: Sequence[Tuple[str, BaseObject]] | Dict[str, BaseObject], allow_dict: bool = True, require_unique_names: bool = False, object_type: type | Tuple[type] | None = None) → bool[source]#

Indicate if input is a sequence of named BaseObject instances.

This can be a sequence of (str, BaseObject instance) tuples or a dictionary with string names as keys and BaseObject instances as values (if allow_dict=True).

Parameters:
seq_to_checkSequence((str, BaseObject)) or Dict[str, BaseObject]

The input to check for conformance with the named object interface. Conforming input are:

  • Sequence that contains (str, BaseObject instance) tuples

  • Dictionary with string names as keys and BaseObject instances as values if allow_dict=True

allow_dictbool, default=True

Whether a dictionary of named objects is allowed as conforming named object type.

  • If True, then a dictionary with string keys and BaseObject instances is allowed format for providing a sequence of named objects.

  • If False, then only sequences that contain (str, BaseObject instance) tuples are considered conforming with the named object parameter API.

require_unique_namesbool, default=False

Whether names used in the sequence of named BaseObject instances must be unique.

  • If True and the names are not unique, then False is always returned.

  • If False, then whether or not the function returns True or False depends on whether seq_to_check follows sequence of named BaseObject format.

object_typeclass or tuple[class], default=None

The class type(s) that is used to ensure that all elements of named objects match the expected type.

Returns:
bool

Whether the input seq_to_check is a sequence that follows the API for nameed base object instances.

Raises:
ValueError

If seq_to_check is not a sequence or allow_dict is False and seq_to_check is a dictionary.

Examples

>>> from predictably._core._base import BaseObject, BaseEstimator
>>> from predictably.validate import is_sequence_named_objects
>>> named_objects = [("Step 1", BaseObject()), ("Step 2", BaseObject())]
>>> is_sequence_named_objects(named_objects)
True

Dictionaries are optionally allowed as sequences of named BaseObjects

>>> dict_named_objects = {"Step 1": BaseObject(), "Step 2": BaseObject()}
>>> is_sequence_named_objects(dict_named_objects)
True
>>> is_sequence_named_objects(dict_named_objects, allow_dict=False)
False

Invalid format due to object names not being strings

>>> incorrectly_named_objects = [(1, BaseObject()), (2, BaseObject())]
>>> is_sequence_named_objects(incorrectly_named_objects)
False

Invalid format due to named items not being BaseObject instances

>>> named_items = [("1", 7), ("2", 42)]
>>> is_sequence_named_objects(named_items)
False

The validation can require the object elements to be a certain class type

>>> named_objects = [("Step 1", BaseObject()), ("Step 2", BaseObject())]
>>> is_sequence_named_objects(named_objects, object_type=BaseEstimator)
False
>>> named_objects = [("Step 1", BaseEstimator()), ("Step 2", BaseEstimator())]
>>> is_sequence_named_objects(named_objects, object_type=BaseEstimator)
True