Merge pull request #621 from catawbasam/master

push!(df, row) for adding rows to a DataFrame

src/DataFrames.jl

@@ -89,7 +89,8 @@ export @~,
        meltdf,
        pivottable,
        read_rda,
-       vecbind
+       vecbind,
+       push!
 
 ##############################################################################
 ##

src/dataframe/dataframe.jl

@@ -999,3 +999,79 @@ function Base.convert(::Type{DataFrame}, A::Matrix)
 end
 nullable!(colnames::Array{Symbol,1},df::AbstractDataFrame)=  (for i in colnames df[i]=DataArray(df[i]) end)
 nullable!(colnums::Array{Int,1},df::AbstractDataFrame)= (for i in colnums df[i]=DataArray(df[i]) end)
+
+
+##############################################################################
+##
+## push! a row onto a DataFrame
+##
+##############################################################################
+
+
+function Base.push!(df::DataFrame, associative::Associative{Symbol,Any})    
+    if length(associative) != length(df.columns)
+        msg = "Length of iterable does not match DataFrame column count."
+        throw(ArgumentError(msg))    
+    end
+    i=1
+    for nm in names(df)
+        try 
+            push!(df[nm], associative[nm])
+        catch
+            #clean up partial row
+            for j in 1:(i-1)
+                pop!(df[ names(df[j]) ])
+            end
+            msg = "Error adding value to column :$nm."
+            throw(ArgumentError(msg))
+        end    
+        i=i+1
+    end
+end
+
+
+function Base.push!{K<:String}(df::DataFrame, associative::Associative{K,Any}) 
+    if length(associative) != length(df.columns)
+        msg = "Length of iterable does not match DataFrame column count."
+        throw(ArgumentError(msg))    
+    end
+    i=1
+    for nm in names(df)
+        try 
+            push!(df[nm], associative[string(nm)])
+        catch
+            #clean up partial row
+            colnames=[symbol(c) for c in names(df)]
+            for j in 1:(i-1)
+                pop!(df[colnames[j]])
+            end
+            msg = "Error adding value to column :$nm."
+            throw(ArgumentError(msg))
+        end    
+        i=i+1
+    end
+end
+
+
+# array and tuple like collections
+function Base.push!(df::DataFrame, iterable::Any)    
+    if length(iterable) != length(df.columns)
+        msg = "Length of iterable does not match DataFrame column count."
+        throw(ArgumentError(msg))    
+    end
+    i=1
+    for t in iterable
+        try 
+            push!(df.columns[i], t)
+        catch
+            #clean up partial row
+            for j in 1:(i-1)
+                pop!(df.columns[j])
+            end
+            msg = "Error adding $t to column :$(names(df)[i]). Possible type mis-match."
+            throw(ArgumentError(msg))
+        end    
+        i=i+1
+    end
+end
+

test/dataframe.jl

@@ -134,4 +134,37 @@ module TestDataFrame
 
     @test hash(convert(DataFrame, [1 2; 3 4])) == hash(convert(DataFrame, [1 2; 3 4]))
     @test hash(convert(DataFrame, [1 2; 3 4])) != hash(convert(DataFrame, [1 3; 2 4]))
+
+
+    # push!(df, row)
+    df=DataFrame( first=[1,2,3], second=["apple","orange","pear"] )
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    push!(dfb, {3,"pear"})
+    @test df==dfb
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    push!(dfb, (3,"pear"))
+    @test df==dfb
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    @test_throws ArgumentError push!(dfb, (33.33,"pear"))
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    @test_throws ArgumentError push!(dfb, ("coconut",22))
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    push!(dfb, [ :first=>3,:second=>"pear" ])
+    @test df==dfb
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    push!(dfb, [ "first"=>3,"second"=>"pear" ])
+    @test df==dfb
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    @test_throws ArgumentError push!(dfb, [ :first=>true,:second=>false ])
+
+    dfb= DataFrame( first=[1,2], second=["apple","orange"] )
+    @test_throws ArgumentError push!(dfb, ["first"=>"chicken", "second"=>"stuff" ])
+
 end