Mailman 3 July 2018 - Pandas-dev

GroupBy Overhaul Proposal
by William Ayd July 19, 2018

July 19, 2018

Hi All, I’ve been thinking through what a redesigned GroupBy module could look like in 1.0. The main problems I am trying to address are: - The current module is relatively convoluted, making contribution and debugging challenging - Behavior is sometimes non-obvious and buggy (see here <https://github.com/pandas-dev/pandas/issues/21790>, here <https://github.com/pandas-dev/pandas/issues/20958> and here <https://github.com/pandas-dev/pandas/issues/20665> as some examples) AND - We violate the mantra of there being “only one obvious way to do things” Along those lines, here were four things I thought could be of immense value: • Removal of apply method • Removal of DataFrameGroupBy and SeriesGroupBy classes • Explicit default column naming • Removal of axis argument These are easier said than done and admittedly controversial. I've pieced together my reasoning and what I think counter arguments could be in the attached documented. I’d be curious to hear everyone’s feedback. - Will

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Pandas Sprint Recap
by Tom Augspurger July 19, 2018

July 19, 2018

Hi all, This week, a group of the pandas maintainers sat down in Austin to talk through the status of the project, and its future direction. I've posted a document on our wiki with a summary of the topics discussed. https://github.com/pandas-dev/pandas/wiki/Pandas-Sprint-(July,-2018) If people have questions or comments, feel free to post here and we'll clarify that document. Tom

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Re: [Pandas-dev] Pandas Sprint Recap
by Irv Lustig July 19, 2018

July 19, 2018

> Stephan Hoyer wrote: > > On Tue, Jul 17, 2018 at 3:47 PM Matthew Rocklin <mrocklin(a)gmail.com> > wrote: > > > Has Pandas ever done a user survey? > > > > I would be curious to know the answer to the question "do you make heavy > > use of the Pandas index" among users, and how that correlates with > > different domain/industry. > > > > This is a great question. I don't think we've ever done this sort of > reserach. > > My suspicion is that most of the time users ignore the index, and find the > way it is used heavily in pandas more annoying than helpful. But certainly > there are some use-cases for which automatic alignment with an index is > fantastic. > For our team, we heavily use the MultiIndex capability for rows (but not columns). Our main use of pandas is to read in data from disparate data sources, and do data wrangling to reshape the data. We do lots of joins/merges of different DataFrames, and placing the keys in a MultiIndex makes it easier to track the join operations. >From our perspective, the MultiIndex on rows is akin to the primary keys of a data table. As we explore data, being able to slice the data along various dimensions is quite valuable. It is also quite natural that a groupby() operation returns a Series or DataFrame with a MultiIndex. What I find a bit frustrating is the lack of symmetry in the API between dealing with the names of a MultiIndex and the names of a column. It's why I created this pull request (https://github.com/pandas-dev/pandas/pull/20046 [ENH: Allow rename_axis to specify index and columns arguments]) and opened this issue https://github.com/pandas-dev/pandas/issues/20421 [API: Allow MultiIndex.rename() to accept a dict as an argument] Dr-Irv

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Welcome Brock Mendel and Marc Garcia to the team
by Joris Van den Bossche July 10, 2018

July 10, 2018

We are happy to announce that Brock Mendel (@jbrockmendel) and Marc Garcia (@datapythonista) have been added to the pandas core team. Amongst many other things, Brock has been working a lot on refactoring the time series related code, and Marc has done amazing work on the documentation. Thanks both, and congratulations! Joris

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ANN: Pandas 0.23.2 Released
by Tom Augspurger July 6, 2018

July 6, 2018

Hi all, I'm happy to announce pandas that pandas 0.23.2 has been released. This is a minor bug-fix release in the 0.23.x series and includes some regression fixes, bug fixes, and performance improvements. We recommend that all users upgrade to this version. See the full whatsnew <https://pandas.pydata.org/pandas-docs/version/0.23.2/whatsnew.html> for a list of all the changes. The release can be installed with conda from the default channel and conda-forge:: conda install pandas Or via PyPI: python -m pip install --upgrade pandas A total of 17 people contributed to this release. People with a “+” by their names contributed a patch for the first time. - David Krych - Jacopo Rota + - Jeff Reback - Jeremy Schendel - Joris Van den Bossche - Kalyan Gokhale - Matthew Roeschke - Michael Odintsov + - Ming Li - Pietro Battiston - Tom Augspurger - Uddeshya Singh - Vu Le + - alimcmaster1 + - david-liu-brattle-1 + - gfyoung - jbrockmendel

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