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