Add insert! and pushfirst!

NEWS.md

@@ -39,6 +39,8 @@
 * Add `resize!`, `keepat!`, `pop!`, `popfirst!`, and `popat!`,
   make `deleteat!` signature more precise
    ([#3047](https://github.com/JuliaData/DataFrames.jl/pull/3047))
+* Add `pushfirst!` and `insert!`
+   ([#3072](https://github.com/JuliaData/DataFrames.jl/pull/3072))
 * New `threads` argument allows disabling multithreading in
   `combine`, `select`, `select!`, `transform`, `transform!`, `subset` and `subset!`
   ([#3030](https://github.com/JuliaData/DataFrames.jl/pull/3030))

docs/src/lib/functions.md

@@ -78,6 +78,7 @@ combine
 fillcombinations
 flatten
 hcat
+insert!
 insertcols
 insertcols!
 invpermute!
@@ -86,6 +87,7 @@ mapcols!
 permute!
 prepend!
 push!
+pushfirst!
 reduce
 repeat
 repeat!

docs/src/man/getting_started.md

@@ -225,7 +225,8 @@ julia> df = DataFrame(A=Int[], B=String[])
 0×2 DataFrame
 ```
 
-Rows can then be added as tuples or vectors, where the order of elements matches that of columns:
+Rows can then be added as tuples or vectors, where the order of elements matches that of columns.
+To add new rows at the end of a data frame use [`push!`](@ref):
 
 ```jldoctest dataframe
 julia> push!(df, (1, "M"))
@@ -261,6 +262,12 @@ Note that constructing a `DataFrame` row by row is significantly less performant
 constructing it all at once, or column by column. For many use-cases this will not matter,
 but for very large `DataFrame`s  this may be a consideration.
 
+If you want to add rows at the beginning of a data frame use [`pushfirst!`](@ref)
+and to insert a row in an arbitrary location use [`insert!`]((@ref)).
+
+You can also add whole tables to a data frame using the [`append!`](@ref)
+and [`prepend!`](@ref) functions.
+
 ### Constructing from another table type
 
 DataFrames supports the [Tables.jl](https://github.com/JuliaData/Tables.jl) interface for

src/DataFrames.jl

@@ -149,6 +149,8 @@ include("abstractdataframe/abstractdataframe.jl")
 include("dataframe/dataframe.jl")
 include("subdataframe/subdataframe.jl")
 include("dataframerow/dataframerow.jl")
+include("dataframe/insertion.jl")
+
 include("groupeddataframe/groupeddataframe.jl")
 include("groupeddataframe/utils.jl")