[Python-ideas] Alternative to PEP 532: delayed evaluation of expressions

[Stephan Hoyer]

On Sun, Nov 6, 2016 at 5:32 PM, Nathaniel Smith <njs at pobox.com> wrote:

> Filtering out a subset of rows from a data frame in pandas; 'height'
> and 'age' refer to columns in the data frame (equivalent to
> data_frame[data_frame["height"] > 100 and data_frame["age"] < 5], but
> more ergonomic and faster (!)):
>
>     data_frame.subset!(height > 100 and age < 5)
>
> (IIRC pandas has at least experimented with various weird lambda hacks
> for this kind of thing; not sure what the current status is.)
>

We abandoned the experiment because we couldn't make it work properly.
There's no way to inject local variables in the appropriate scope around
the lambda function:
https://github.com/pandas-dev/pandas/issues/13040
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