circuitpython/docs/library/collections.rst

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:mod:`collections` -- collection and container types
=====================================================
.. include:: ../templates/unsupported_in_circuitpython.inc
.. module:: collections
:synopsis: collection and container types
|see_cpython_module| :mod:`cpython:collections`.
This module implements advanced collection and container types to
hold/accumulate various objects.
Classes
-------
.. function:: namedtuple(name, fields)
This is factory function to create a new namedtuple type with a specific
name and set of fields. A namedtuple is a subclass of tuple which allows
to access its fields not just by numeric index, but also with an attribute
access syntax using symbolic field names. Fields is a sequence of strings
specifying field names. For compatibility with CPython it can also be a
a string with space-separated field named (but this is less efficient).
Example of use::
from collections import namedtuple
MyTuple = namedtuple("MyTuple", ("id", "name"))
t1 = MyTuple(1, "foo")
t2 = MyTuple(2, "bar")
print(t1.name)
assert t2.name == t2[1]
.. function:: OrderedDict(...)
``dict`` type subclass which remembers and preserves the order of keys
added. When ordered dict is iterated over, keys/items are returned in
the order they were added::
from collections import OrderedDict
# To make benefit of ordered keys, OrderedDict should be initialized
# from sequence of (key, value) pairs.
d = OrderedDict([("z", 1), ("a", 2)])
# More items can be added as usual
d["w"] = 5
d["b"] = 3
for k, v in d.items():
print(k, v)
Output::
z 1
a 2
w 5
b 3