Materialize DataFrame(Rows|Columns) as DataFrame

JuliaData · Dec 20, 2019 · 9ebbf6f · 9ebbf6f
1 parent 4d323ca
commit 9ebbf6f
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Showing 2 changed files with 4 additions and 18 deletions.
diff --git a/src/other/tables.jl b/src/other/tables.jl
@@ -54,22 +54,8 @@ Tables.rowaccess(::Type{<:Union{DataFrameRows,DataFrameColumns}}) = true
 Tables.columns(itr::Union{DataFrameRows,DataFrameColumns}) = Tables.columns(parent(itr))
 Tables.rows(itr::Union{DataFrameRows,DataFrameColumns}) = Tables.rows(parent(itr))
 Tables.schema(itr::Union{DataFrameRows,DataFrameColumns}) = Tables.schema(parent(itr))
-Tables.materializer(itr::DataFrameRows) =
-    eachrow ∘ prefer_singleton_callable(Tables.materializer(parent(itr)))
-function Tables.materializer(itr::DataFrameColumns)
-    f = prefer_singleton_callable(Tables.materializer(parent(itr)))
-    if eltype(itr) <: Pair
-        return x -> eachcol(f(x), true)
-    else
-        return x -> eachcol(f(x), false)
-    end
-end
-
-# A hack to workaround the type-instability of `∘`:
-prefer_singleton_callable(::Type{T}) where T = SingletonCallable{T}()
-prefer_singleton_callable(f) = f
-struct SingletonCallable{T} end
-(::SingletonCallable{T})(x) where T = T(x)
+Tables.materializer(itr::Union{DataFrameRows,DataFrameColumns}) =
+    Tables.materializer(parent(itr))
 
 IteratorInterfaceExtensions.getiterator(df::AbstractDataFrame) = Tables.datavaluerows(df)
 IteratorInterfaceExtensions.isiterable(x::AbstractDataFrame) = true

diff --git a/test/tables.jl b/test/tables.jl
@@ -58,16 +58,16 @@ Base.propertynames(d::DuplicateNamesColumnTable) = (:a, :a, :b)
 
     @testset "basics $(nameof(typeof(table)))" for table in [
         df,
+        view(df, :, :),
         eachrow(df),
         eachcol(df),
-        eachcol(df, true),
     ]
         @test Tables.istable(table)
         @test Tables.rowaccess(table)
         @test Tables.columnaccess(table)
         @test Tables.schema(table) === Tables.Schema((:a, :b), Tuple{Int64, Symbol})
         @test Tables.schema(table) == Tables.schema(Tables.rows(table)) == Tables.schema(Tables.columns(table))
-        @test @inferred(Tables.materializer(table)(Tables.columns(table))) isa typeof(table)
+        @test @inferred(Tables.materializer(table)(Tables.columns(table))) isa DataFrame
 
         row = first(Tables.rows(table))
         @test propertynames(row) == (:a, :b)