Change DataSeries>>#summary to bring it more in line with Python's pandas describe() by adding Count and Stdev, renaming 1st Qu., Median, 3rd Qu. to 25%, 50% and 75%, as well as reordening the list.

Author: svenvc

src/DataFrame-Tests/DataSeriesTest.class.st

@@ -2295,8 +2295,8 @@ DataSeriesTest >> testStatsSummary [
 	| expected actual |
 
 	expected := DataSeries
-		withKeys: #(Min '1st Qu.' Median Average '3rd Qu.' Max)
-		values: { 3 . 7 . 9 . (115 / 11) . 15 . 20 }
+		withKeys: #(Count Average Stdev Min '25%' '50%' '75%' Max)
+		values: { 11 . series values average . series values stdev . 3 . 7 . 9 .  15 . 20 }
 		name: series name.
 
 	actual := series summary.

src/DataFrame/DataSeries.class.st

@@ -1055,18 +1055,22 @@ DataSeries >> sum [
 
 { #category : #statistics }
 DataSeries >> summary [
-	"A data series is returned which is a statistical summary of the data series. With keys as different statistical measures and values as the values returned when those statistical measures are applied on the data series."
+	"A data series is returned which is a statistical summary of the data series. 
+	With keys as different statistical measures and values as the values returned
+	when those statistical measures are applied on the data series."
 
 	| summary |
 	summary := self species new.
 	summary name: self name.
 
 	summary
-		at: 'Min' put: self min;
-		at: '1st Qu.' put: self firstQuartile;
-		at: 'Median' put: self median;
+		at: 'Count' put: self size;
 		at: 'Average' put: self average;
-		at: '3rd Qu.' put: self thirdQuartile;
+		at: 'Stdev' put: self stdev;
+		at: 'Min' put: self min;
+		at: '25%' put: self firstQuartile;
+		at: '50%' put: self median;
+		at: '75%' put: self thirdQuartile;
 		at: 'Max' put: self max.
 
 	^ summary