DataFrames.jl has this too
julia> df = DataFrame();
julia> push!(df, (a =1, b = 2))
1×2 DataFrame
Row │ a b
│ Int64 Int64
─────┼──────────────
1 │ 1 2
julia> push!(df, (a =3, b = missing); promote = true)
2×2 DataFrame
Row │ a b
│ Int64 Int64?
─────┼────────────────
1 │ 1 2
2 │ 3 missing