nushell/crates/nu-cmd-dataframe
WMR b67b6f7fc5
Add a datepart expression for dfr to be used with dfr with-column (#9285)
# Description

Today the only way to extract date parts from a dfr series is the dfr
get-* set of commands. These create a new dataframe with just the
datepart in it, which is almost entirely useless. As far as I can tell
there's no way to append it as a series in the original dataframe. In
discussion with fdncred on Discord we decided the best route was to add
an expression for modifying columns created in dfr with-column. These
are the way you manipulate series within a data frame.

I'd like feedback on this approach - I think it's a fair way to handle
things. An example to test it would be:

```[[ record_time]; [ (date now)]]  | dfr into-df | dfr with-column [ ((dfr col record_time) | dfr datepart nanosecond | dfr as "ns" ), (dfr col record_time | dfr datepart second | dfr as "s"), (dfr col record_time | dfr datepart minute | dfr as "m"), (dfr col record_time | dfr datepart hour | dfr as "h") ]```

I'm also proposing we deprecate the dfr get-* commands.  I've not been able to figure out any meaningful way they could ever be useful, and this approach makes more sense by attaching the extracted date part to the row in the original dataframe as a new column.

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# User-Facing Changes

add in dfr datepart as an expression
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# Tests + Formatting
Need to add some better assertive tests.  I'm also not sure how to properly write the test_dataframe at the bottom, but will revisit as part of this PR.  Wanted to get feedback early.

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---------

Co-authored-by: Robert Waugh <robert@waugh.io>
2023-05-30 09:41:18 -05:00
..
src Add a datepart expression for dfr to be used with dfr with-column (#9285) 2023-05-30 09:41:18 -05:00
Cargo.toml update most dependencies except where deeper code changes are needed (#9296) 2023-05-26 10:32:48 -05:00
LICENSE move dataframe commands to nu-cmd-dataframe (#9241) 2023-05-19 10:56:08 -07:00