DataFrames: obtaining the subset of rows by a set of values

New to Julia
41 
iris |> 
Filter(Species -> Species == "versicolor") |>
Map((SepalLength, SepalWidth) -> SepalLength / SepalWidth)

This scares me a bit because it means that fast filtering would have to happen with variables themselves, named in the code, instead of with functions, due to the non-standard evaluation. It’s an R-ism that I want to avoid if possible.

42

I’ve opened a WIP PR in DataFrames about using the select approach for combining results of a grouping operations: https://github.com/JuliaData/DataFrames.jl/pull/1601

43

Could you please clarify how to type in the Greek symbol on the REPL?

I tried \epsilon but this is not the correct symbol.

I mean the symbol that is written here: filter(row → row.col ∈ [1,2,3], df)

Thanks!

44

\in

45

When in doubt ask the REPL:

help?> ζ
"ζ" can be typed by \zeta<tab>

help?> ∈
"∈" can be typed by \in<tab>
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