Julia Data Frame Binding String

Question

How to add one data frame to another, similar to SQL union or R rbind ?

Say I have data frames A and B defined as follows.

 A = DataFrame(x = [1, 2, 3], y = [4, 5, 6]) B = DataFrame(x = [4, 5, 6], y = [7, 8, 9]) 

One way to get closer to this would be:

 C = deepcopy(A) for i = 1:size(B, 1) push!(C, Array(B[i,:])) end 

While this works, it seems to me that it is a bit hacked. Is there a better or more idiomatic way to do this?

Answer 1

Concatenating the array [A;B] is the easiest way to add rows from one DataFrame to another:

 julia> A = DataFrame(x = [1, 2, 3], y = [4, 5, 6]); julia> B = DataFrame(x = [4, 5, 6], y = [7, 8, 9]); julia> [A;B] 6x2 DataFrames.DataFrame | Row | x | y | |-----|---|---| | 1 | 1 | 4 | | 2 | 2 | 5 | | 3 | 3 | 6 | | 4 | 4 | 7 | | 5 | 5 | 8 | | 6 | 6 | 9 |