Add drop column method and test.

Add test for shuffling a data frame

src/DataFrame-Tests/DataFrameTest.class.st

@@ -922,6 +922,19 @@ DataFrameTest >> testColumns [
 	self assert: df columns equals: expectedCollection
 ]
 
+{ #category : 'tests' }
+DataFrameTest >> testColumnsAllBut [
+
+	| expectedDataFrame |
+	expectedDataFrame := DataFrame withRows: #( #( 'Barcelona' 1.609 ) #( 'Dubai' 2.789 ) #( 'London' 8.788 ) ).
+	expectedDataFrame rowNames: #( 'A' 'B' 'C' ).
+	expectedDataFrame columnNames: #( 'City' 'Population').
+
+	self 
+		assert: (df columnsAllBut: #(BeenThere)) 
+		equals: expectedDataFrame
+]
+
 { #category : 'tests' }
 DataFrameTest >> testColumnsAt [
 
@@ -5171,22 +5184,24 @@ DataFrameTest >> testShuffledWithSeed [
 
 	| expected |
 
-	"df = A Barcelona B Dubai C London"
 	expected := DataFrame withRows: #(
 		('Barcelona' 1.609 true)
    		('London' 8.788 false)
 		('Dubai' 2.789 true)).
+	expected rowNames: #( 'A' 'C' 'B').
+	expected columnNames: #( 'City' 'Population' 'BeenThere' ).
 
 	self assert: (df shuffleWithSeed: 1) equals: expected.
-
-	self assert: (df shuffleWithSeed: 2) equals: expected.
 
 	expected := DataFrame withRows: #(
-   		('London' 8.788 false)
-		('Barcelona' 1.609 true)		
-		('Dubai' 2.789 true)).
+		('Dubai' 2.789 true)	
+		('Barcelona' 1.609 true)
+   		('London' 8.788 false) ).
+	expected rowNames: #('B' 'A' 'C').
+	expected columnNames: #( 'City' 'Population' 'BeenThere' ).	
+	self assert: (df shuffleWithSeed: 2) equals: expected.
 
-	self assert: (df shuffleWithSeed: 3) equals: expected.
+
 ]
 
 { #category : 'tests' }

src/DataFrame/DataFrame.class.st

@@ -851,6 +851,13 @@ DataFrame >> columns: anArrayOfColumnNames put: anArrayOfArrays [
 		self column: name put: array ]
 ]
 
+{ #category : 'accessing' }
+DataFrame >> columnsAllBut: aCollectionOfColumnNames [
+	"Returns a <Collection> of except those present in aCollectionOfColumnNames"
+
+	^ self columns: (self columnNames copyWithoutAll: aCollectionOfColumnNames)
+]
+
 { #category : 'accessing' }
 DataFrame >> columnsAt: anArrayOfNumbers [
 	"Returns a collection of columns whose column indices are present in the array anArrayOfNumbers"
@@ -2441,6 +2448,12 @@ DataFrame >> shuffleWithSeed: aNumber [
 	^ self shuffleBy: (Random new seed: aNumber)
 ]
 
+{ #category : 'accessing' }
+DataFrame >> shuffled [
+
+	self shuffleBy: Random new
+]
+
 { #category : 'accessing' }
 DataFrame >> size [
 	"Returns the number of rows of a DataFrame"