Itermark

Extension for iterable data types; adds boundwise bookmark iteration, enabling active item tracking/setting (type allowing)

Ideal for 'paging' through iterables

Installation

pip install itermark

Using Itermark

>>> from itermark import Itermark
>>> iterlist = Itermark(['zero', 'one', 'two', 'three'])
>>> iterlist.active
'zero'
>>> iterlist.mark += 2
>>> iterlist.active
'two'
>>> iterlist.mark = 5   # Would put mark outside active index
>>> iterlist.active
'three'                 # Defaults to highest upper bound
>>> iterlist.active = 'new three'
>>> iterlist.active
'new three'

The Itermark extension adds two properties (three for dicts), and two functions to it's objects. Note that all itermark attributes are disabled if underlying iterable is empty

mark

Acts as a bookmark index, and can be assigned a value directly (iterlist.mark = 2) or by operator assignment (iterlist.mark += 1, iterlist.mark -= 1)

active

Retrieves nth item from iterable where self.mark = n. Dictionary Itermarks return nth value

activekey

Dict specific, retrieves nth key from dictonary type where self.mark = n. Note that itermark was made post 3.6's insertion ordered dicts. While itermark properties still work pre 3.6, collections.OrderedDict is recommended and supported

markend()

Set mark to end value. Mark will never go above upper bound, but without calling len() user may not know what that upper bound is. Use .markend() to reliably set mark to upper bound

Supported types

list

Original implementation, full mark and active usage

`tuple

No active assignment `

dict

Uses iterator gen for mark and active properties. active calls and sets values, activekey calls immutable keys

OrderedDict

Same features as a regular dict, but for pre 3.6 implementation

string

Sure, strings are just a list of characters

set

Look, I don't know who'd want bookmark iteration through a set but here ya go