Save OrderedDict imports in various stdlibs.

[methane]

BPO	32360
Nosy	@rhettinger, @methane, @serhiy-storchaka, @miss-islington
PRs	bpo-32360: Remove OrderedDict reference as dicts are ordered now #4994 bpo-32360: Replace OrderedDict with dict in inspect.py module #5000 bpo-32360: Remove object_pairs_hook=OrderedDict examples #5001 bpo-32360: Remove OrderedDict from re module #5013 bpo-32360: Remove OrderedDict usage from json.tool #5315 [3.7] bpo-32360: Remove object_pairs_hook=OrderedDict examples (GH-5001) #6361
Dependencies	bpo-32336: Save OrderedDict import in argparse bpo-32338: Save OrderedDict import in re

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2018-04-03.06:12:08.011>
created_at = <Date 2017-12-18.09:45:46.761>
labels = ['3.7', 'library', 'performance']
title = 'Save OrderedDict imports in various stdlibs.'
updated_at = <Date 2018-04-03.06:12:08.009>
user = 'https://github.com/methane'

bugs.python.org fields:

activity = <Date 2018-04-03.06:12:08.009>
actor = 'methane'
assignee = 'none'
closed = True
closed_date = <Date 2018-04-03.06:12:08.011>
closer = 'methane'
components = ['Library (Lib)']
creation = <Date 2017-12-18.09:45:46.761>
creator = 'methane'
dependencies = ['32336', '32338']
files = []
hgrepos = []
issue_num = 32360
keywords = ['patch']
message_count = 9.0
messages = ['308538', '308974', '308983', '308984', '308987', '309008', '310670', '314858', '314860']
nosy_count = 4.0
nosy_names = ['rhettinger', 'methane', 'serhiy.storchaka', 'miss-islington']
pr_nums = ['4994', '5000', '5001', '5013', '5315', '6361']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue32360'
versions = ['Python 3.7']

[methane]

csv and re has issues already.
There are some remaining OrderdDict, including docstring.
It looks like some of them can be removed easily without doc update.

This is ag --exclude-dir=test OrderedDict, exluding csv, re, pprint and collections.

typing:
2109: nm_tpl.__annotations__ = nm_tpl._field_types = collections.OrderedDict(types)

unittest/util.py
3:from collections import namedtuple, OrderedDict
158: c = OrderedDict()

enum.py
153: enum_class._member_map_ = OrderedDict() # name->value map
615: # We use an OrderedDict of sorted source keys so that the

lib2to3/pgen2/grammar.py
91: dump() recursively changes all dict to OrderedDict, so the pickled file
93: pickled file to create the tables, but only changes OrderedDict to dict
94: at the top level; it does not recursively change OrderedDict to dict.
96: passed to load() in that some of the OrderedDict (from the pickled file)
98: performance because OrderedDict uses dict's __getitem__ with nothing in
142: return collections.OrderedDict(

asyncio/base_events.py
842: addr_infos = collections.OrderedDict()

configparser.py
142:from collections import OrderedDict as _default_dict, ChainMap as _ChainMap

inspect.py
52:from collections import namedtuple, OrderedDict
1712: new_params = OrderedDict(old_params.items())
2563: * arguments : OrderedDict
2663: self.arguments = OrderedDict(new_arguments)
2694: * parameters : OrderedDict
2724: params = OrderedDict()
2727: params = OrderedDict()
2762: params = OrderedDict(((param.name, param)
2839: arguments = OrderedDict()

json/tool.py
41: object_pairs_hook=collections.OrderedDict)

json/__init__.py
31:    >>> from collections import OrderedDict
32:    >>> mydict = OrderedDict([('4', 5), ('6', 7)])
290:    collections.OrderedDict will remember the order of insertion). If
318:    collections.OrderedDict will remember the order of insertion). If

json/decoder.py
297: collections.OrderedDict will remember the order of insertion). If

email/_header_value_parser.py
73:from collections import OrderedDict
720: params = OrderedDict()

pydoc_data/topics.py
8585: '"collections.OrderedDict" to remember the order that class '
8593: ' return collections.OrderedDict()\n'
8614: 'empty "collections.OrderedDict". That mapping records the '

[rhettinger]

These should be looked at one at a time (no sweeping search and replace missions).

The original author should be consulted when possible (they are in a better position to judge whether the original intent was preserved).

Published APIs should not be changed (i.e. you can't just change the default argument for configparser).

Docs should be changed carefully (i.e. let Bob Ippolito decide whether he wants to change the examples of how to use the object_pairs_hook).

Guido was very clear that you can't just downgrade every occurrence of OrderedDict with dict. Please don't be so aggressive (grepping every occurrence in the standard library without giving it individual consideration).

[methane]

Agreed.
I won't remove OrderedDict usages which is part of public APIs.
This issue is for finding and removing easy local usages.

[methane]

Let's remove from these:

• asyncio/base_events.py: Used for local variable.
• email/_header_value_parser.py: Used for local variable.
• json: Examples (in document and docstring) for keeping order, and json.tool.

I don't touch other modules.

[serhiy-storchaka]

I concur with Raymond. I made the same searching before and have found that there are not much opportunities for getting rid of OrderedDict and there are even less cases that will get a benefit from this.

[rhettinger]

• asyncio/base_events.py: Used for local variable.
• email/_header_value_parser.py: Used for local variable.
• json: Examples (in document and docstring) for keeping order, and json.tool.

All of these modules have active maintainers. You should create separate issues for each one of these and assign to those maintainers. You don't just get to mow down all the other developers. That isn't how we work together.

In the JSON module, there does need to be an example of how to use object_pairs_hook, so you will need to come up with a replacement or an additional note explaining in Py3.7 and later, most of the OrderedDict use cases have been supplanted by the regular dict.

[methane]

New changeset 2812d3d by INADA Naoki in branch 'master':
bpo-32360: Remove OrderedDict usage from json.tool (GH-5315)
2812d3d

[methane]

New changeset 629338f by INADA Naoki in branch 'master':
bpo-32360: Remove object_pairs_hook=OrderedDict examples (GH-5001)
629338f

[miss-islington]

New changeset 0c53357 by Miss Islington (bot) in branch '3.7':
bpo-32360: Remove object_pairs_hook=OrderedDict examples (GH-5001)
0c53357