Converting Dict to DataFrames

New to Julia
, ,
1

Hi all,
I’m sure this is pretty simple but it’s tripping me up.
Say I have a dictionary as such:

using DataFrames
using Dates

Dates_to_remember = Dict(:Birthday=> Set([
    Date("2021-01-15"),
    Date("1991-08-30"),
    Date("1954-07-01")
]),
:Anniversary => Set([
    Date("1997-01-25"),
    Date("2017-09-30")
]))

How can I transform this so that the output looks like this?:

transformed_output = DataFrame(:Date=>["2021-01-15","1991-08-30","1954-07-01","1997-01-25","2017-09-30"],:Category=>["Birthday","Bithday","Birthday","Anniversary","Anniversary"])

I’ve tried using values() but that gets me the set. I can’t really figure out how to get the values within the set to put into the DF.

Thanks for your help!
Snowy

2

This is one option:

julia> flatten(stack(DataFrame(Dates_to_remember), :), :value)
5×2 DataFrame
 Row │ variable     value      
     │ String       Date       
─────┼─────────────────────────
   1 │ Anniversary  2017-09-30
   2 │ Anniversary  1997-01-25
   3 │ Birthday     1991-08-30
   4 │ Birthday     2021-01-15
   5 │ Birthday     1954-07-01
2 Likes
3

Or more straightforward:

transformed_output = DataFrame()
for (k,v) in Dates_to_remember
    for d in v
        push!(transformed_output, (Date=d, Category=k))
    end
end

Use string(d) and string(k) if you want strings.

1 Like
4

These are great functions I didn’t know existed.
Thank you to you both!

5

I think the whole thing can be written as simply as:

DataFrame((Date=d, Category=k) for (k,v) in Dates_to_remember for d in v)
1 Like