Join two dataframes with two common column headers

New to Julia
1

I have two data frames. The first, A, contains the headings “Timestamp”, “Ticker”, “Price”. The second, B, contains “Timestamp”, “Ticker”, “ProfitMargin”.

How do I join A and B, such that I get:

C = [Timestamp, Ticker, Price, ProfitMargin] for only those Timestamp values that are shared between A and B, and without having duplicate headers?

2

In the DataFrames.jl documentation are quite a few examples on how to join two data frames.

https://dataframes.juliadata.org/stable/man/joins/

If I read your example right you want to innerjoin the two data frames A and B.

julia> A = DataFrame(Timestamp = [1, 2, 3], Ticker = ["a", "b", "c"], Price = [1.0, 2.0, 3.0])
3×3 DataFrame
 Row │ Timestamp  Ticker  Price   
     │ Int64      String  Float64 
─────┼────────────────────────────
   1 │         1  a           1.0
   2 │         2  b           2.0
   3 │         3  c           3.0

julia> B = DataFrame(Timestamp = [2, 3, 4], Ticker = ["b", "c", "a"], ProfitMargin = [10.0, 20.0, 30.0])
3×3 DataFrame
 Row │ Timestamp  Ticker  ProfitMargin 
     │ Int64      String  Float64      
─────┼─────────────────────────────────
   1 │         2  b               10.0
   2 │         3  c               20.0
   3 │         4  a               30.0

julia> C = innerjoin(A, B, on = [:Timestamp, :Ticker])
2×4 DataFrame
 Row │ Timestamp  Ticker  Price    ProfitMargin 
     │ Int64      String  Float64  Float64      
─────┼──────────────────────────────────────────
   1 │         2  b           2.0          10.0
   2 │         3  c           3.0          20.0
1 Like