Views Module

Module: piethorn.collections.views

Overview

This module provides read-only wrappers over sequences and mappings.

• SequenceView Type
• MapView Type

SequenceView

class SequenceView(origin, *, reverse=False, cut=None)

Read-only view over an existing sequence.

Main properties

origin_size

Length of the original sequence.

is_reversed

Whether iteration is reversed.

parent / has_parent

Parent view information for nested views.

cut / has_cut

Normalized slice applied to the origin.

Example

from piethorn.collections.views import SequenceView

view = SequenceView([1, 2, 3, 4], reverse=True, cut=slice(1, 4))
nested = view[1:]

list(view)     # [4, 3, 2]
view[1]        # 3
list(nested)   # [3, 2]

Methods

count(value)

Count occurrences in the visible region.

index(value, start=0, stop=None)

Return the view-local index of a value.

MapView

class MapView(origin)

Immutable wrapper around a mapping.

Example

from piethorn.collections.views import MapView

view = MapView({"left": 1, "right": 2})
view["left"]         # 1
view.get("none", 5)  # 5

Autodoc