ddp_utils.ulist

import ddp_utils.ulist

Order-preserving deduplication, predicate lookup and list chunking.

Examples

Use this public operation:

import ddp_utils.ulist

ddp_utils.ulist.unique(seq: Iterable[T]) → List[T]

Return a list containing the first occurrence of each distinct item.

Parameters

Name	Type	Description
seq	Iterable[T]	Iterable of hashable items; consumed once, without modifying it.

Returns

Type	Description
List[T]	New list in encounter order; an empty iterable returns [].

Raises

Exception	Description
TypeError	An item is unhashable, for example a dict or list.

Examples

Use this public operation:

result = ddp_utils.ulist.unique(seq=seq_value)

ddp_utils.ulist.find(seq: Iterable[T], pred: Callable[[T], bool]) → T | None

Return the first item for which pred(item) is truthy, or None.

Parameters

Name	Type	Description
seq	Iterable[T]	Iterable searched in order; generators are consumed until a match.
pred	Callable[[T], bool]	Callable tested once per visited item; its exceptions propagate.

Returns

Type	Description
T | None	The original matching object, including a falsy item such as 0; None for no match. A matched None cannot be distinguished from no match.

Examples

Use this public operation:

result = ddp_utils.ulist.find(seq=seq_value, pred=pred_value)

ddp_utils.ulist.chunk(seq: List[T], size: int) → List[List[T]]

Return consecutive slices of a list using a range step.

Parameters

Name	Type	Description
seq	List[T]	List to split; the input is not mutated and elements are not copied.
size	int	Positive chunk size. Zero raises; negative values return [].

Returns

Type	Description
List[List[T]]	A list of lists, with a possibly shorter last chunk; [] for empty input.

Raises

Exception	Description
ValueError	size is zero, even for an empty list.
TypeError	size is not accepted as a range step.

Examples

Use this public operation:

result = ddp_utils.ulist.chunk(seq=seq_value, size=size_value)