itemgetter add dict example

[twz915]

The document says that operator.itemgetter using the operand’s __getitem__() method. However, it is difficult to understand for a newbie.
One example is better than thousands of words.

[mention-bot]

@twz915, thanks for your PR! By analyzing the history of the files in this pull request, we identified @birkenfeld, @benjaminp and @tiran to be potential reviewers.

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[louisom]

I think this shouldn't put here, this code block is for explaining Lists, tuples, and strings accept an index or a slice:, not Dictionaries accept any hashable value.

If we want to add a new example for dictionaries, it should make a new code block above this one.

[bitdancer]

Actually, this makes the example exactly parallel the paragraph it follows, showing the dictionary example first, then the index, and then the slice, in the order they are mentioned in the text. Breaking the paragraph up with the example would not improve the flow, in my opinion. The fact that dictionary is in a separate sentence doesn't matter that much, I think.

[serhiy-storchaka]

I think existing words are enough for explaining operator.itemgetter. Open an issue on the bug tracker for discussion.

[vstinner]

@twz915: Hi, would you mind to open a bug on bugs.python.org and sign the CLA please? Otherwise, we will be unable to accept your contribution and will have to close your PR :-(

[terryjreedy]

I think that this qualifies at the upper edge of trivial, so that no issue or CLA is needed.
Brett, do we have a specific rule on number of characters or words?
That mean this is also at the upper edge of what does not need a Misc/ACK entry.

[terryjreedy]

I agree with Bitdancer that this fits nicely at the proposed location. The itemgetter concept is not initially trivial and I think that this helps a bit. If not for other opinions, I would merge it.

[twz915]

@terryjreedy That's why I added the snippet. I think it is a good example to help users to understand itemgetter and list's List[x] or dict's Dict[x] behavior better.

[twz915]

@Haypo I don't think this is a bug, and add the example is just used to contribute a better understanding.

[terryjreedy]

@twz915 Some people say 'bug' when they really mean 'issue'. The issues on the site include enhancement requests and performance improvements. The site could have been called 'issues/python/org' or 'tracker/python/org', but someone named it 'bugs/python/org'.

[terryjreedy]

The other interpretation is that a 'bug' is a report of something that 'bugs' the person who opens the issue. You were 'bugged' by the absence of a mapping example. Once an issue is open, we carefully classify it as about (bad) behavior, enhancement, performance, security, or something else.

[vstinner]

Sorry, I requested an issue before reading the PR. I read your PR, I agree that no issue is required here.

[ned-deily]

Since this is such a trivial change, I have merged it. Thanks, @twz915, for your contribution. Please fill out the contributor form for any future contributions.