coverart_utils.SortedCollection Class Reference

List of all members.

Public Member Functions
def	__init__
def	clear
def	copy
def	__len__
def	__getitem__
def	__iter__
def	__reversed__
def	__repr__
def	__reduce__
def	__contains__
def	index
def	count
def	insert
def	reorder
def	insert_all
def	remove
Properties
	key = property(_getkey, _setkey, _delkey, 'key function')

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Detailed Description

Sequence sorted by a key function.

SortedCollection() is much easier to work with than using bisect() directly.
It supports key functions like those use in sorted(), min(), and max().
The result of the key function call is saved so that keys can be searched
efficiently.

Instead of returning an insertion-point which can be hard to interpret, the
five find-methods return a specific item in the sequence. They can scan for
exact matches, the last item less-than-or-equal to a key, or the first item
greater-than-or-equal to a key.

Once found, an item's ordinal position can be located with the index() method.
New items can be added with the insert() and insert_right() methods.
Old items can be deleted with the remove() method.

The usual sequence methods are provided to support indexing, slicing,
length lookup, clearing, copying, forward and reverse iteration, contains
checking, item counts, item removal, and a nice looking repr.

Finding and indexing are O(log n) operations while iteration and insertion
are O(n).  The initial sort is O(n log n).

The key function is stored in the 'key' attibute for easy introspection or
so that you can assign a new key function (triggering an automatic re-sort).

In short, the class was designed to handle all of the common use cases for
bisect but with a simpler API and support for key functions.

>>> from pprint import pprint
>>> from operator import itemgetter

>>> s = SortedCollection(key=itemgetter(2))
>>> for record in [
...         ('roger', 'young', 30),
...         ('angela', 'jones', 28),
...         ('bill', 'smith', 22),
...         ('david', 'thomas', 32)]:
...     s.insert(record)

>>> pprint(list(s))         # show records sorted by age
[('bill', 'smith', 22),
 ('angela', 'jones', 28),
 ('roger', 'young', 30),
 ('david', 'thomas', 32)]

>>> s.find_le(29)           # find oldest person aged 29 or younger
('angela', 'jones', 28)
>>> s.find_lt(28)           # find oldest person under 28
('bill', 'smith', 22)
>>> s.find_gt(28)           # find youngest person over 28
('roger', 'young', 30)

>>> r = s.find_ge(32)       # find youngest person aged 32 or older
>>> s.index(r)              # get the index of their record
3
>>> s[3]                    # fetch the record at that index
('david', 'thomas', 32)

>>> s.key = itemgetter(0)   # now sort by first name
>>> pprint(list(s))
[('angela', 'jones', 28),
 ('bill', 'smith', 22),
 ('david', 'thomas', 32),
 ('roger', 'young', 30)]

Definition at line 139 of file coverart_utils.py.

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Member Function Documentation

def coverart_utils.SortedCollection.reorder	(		self,
			item
	)

Reorder an item. If its key changed, then the item is
repositioned, otherwise the item stays untouched

Definition at line 285 of file coverart_utils.py.

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The documentation for this class was generated from the following file:

• /home/foss/Downloads/coverart-browser/coverart_utils.py