# Applying group selection conditions using groupeddataframes

**URL:** <https://discourse.julialang.org/t/applying-group-selection-conditions-using-groupeddataframes/46060>\
**Category:** New to Julia\
**Tags:** dataframes\
**Created:** [September 4, 2020, 1:41pm UTC](https://discourse.julialang.org/t/applying-group-selection-conditions-using-groupeddataframes/46060 "2020-09-04T13:41:17Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![jo-fleck](https://avatars.discourse-cdn.com/v4/letter/j/59ef9b/32.png) [@jo-fleck](https://discourse.julialang.org/u/jo-fleck)\
**Post date:** [September 6, 2020, 10:58am UTC](https://discourse.julialang.org/t/applying-group-selection-conditions-using-groupeddataframes/46060/13 "2020-09-06T10:58:16Z")

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Thanks a lot @kmundnic! `process2` is helpful for me because it uses syntax I am familiar with and still improves performance.

Since I am new to groupedddataframes it would be helpful to get a snapshot on the current frontier regarding data selection. Specifically, is there currently an efficient way to

- use logical indexing on rows of groupedddataframes? (I only found [those](https://juliadata.github.io/DataFrames.jl/stable/lib/indexing/#Indexing-GroupedDataFrames) indexing options.)
- apply selection functions such as `filter` on groupedddataframes? ([This question](https://discourse.julialang.org/t/filter-doesnt-work-on-grouped-dataframe/27322) seems related.)

Thanks a lot to everyone!

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