ENH: add Series.info

[MarcoGorelli]

• initial draft to close API: add Series.info method #5167
• tests added / passed
• passes black pandas
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

screenshot of the example

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Note to self: this change from ba72b59b44f15076877e784e16cbc66aa03e0adc breaks the tests

-    # groupby dtype.name to collect e.g. Categorical columns
-    counts = data.dtypes.value_counts().groupby(lambda x: x.name).sum()
+    counts = data._data.get_dtype_counts()

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Updated

Currently, looks like this:

[MarcoGorelli]

Some screenshots

[pep8speaks]

Hello @MarcoGorelli! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2020-09-19 16:26:44 UTC

[MarcoGorelli]

Thanks @WillAyd for your review, have updated

[jreback]

so, before doing this, can you do a pre-cursor which moves the .info code into pandas/io/formats/info.py. we already have way too many things inside the core/frame.py and core/generic.py modules. I think this would promote easy sharing of this code. also happy for the added tests, you can move them as well to pandas/io/formats/test_info.py

[MarcoGorelli]

Screenshots of docs:

[WillAyd]

Hmm I think this is confusing to have col_count be populated by a Series in some cases - can you think of a way to refactor?

[MarcoGorelli]

@WillAyd sure, have given this a go

[MarcoGorelli]

I've pushed a new attempt at this. I've factored out some pieces of _verbose_repr to avoid code duplication, although their arguments lists and return values have become rather long.

[WillAyd]

@MarcoGorelli can you fix up the PR here? Someone will take a look again thereafter

[MarcoGorelli]

@MarcoGorelli can you fix up the PR here? Someone will take a look again thereafter

@WillAyd Sure, have given another go at it, now using a namedtuple to group together some similar variables

[WillAyd]

I think this is headed in the right direction

[WillAyd]

Can you generate this using collections.namedtuple instead? We typically don't subclass things from typing

[MarcoGorelli]

Sure, can do, although I think this is the newer syntax, it's taken directly from https://docs.python.org/3/library/typing.html#typing.NamedTuple

They also recommend it in the mypy docs: https://mypy.readthedocs.io/en/stable/kinds_of_types.html#named-tuples

[MarcoGorelli]

(closing as @ivanovmg will take it over)