CHANGELOG; Err deprecation

CHANGELOG.md

@@ -5,15 +5,23 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This document follows
 [markdownlint](https://github.com/markdownlint/markdownlint) formatting rules.
 
-## [0.12.0]
+## [0.12.0] - 2021-10-10
 
 ### Added in 0.12.0
 
+- Add dataframe.GetGroups (@arjunmahishi)
+- Add Series.Slice (@jfussion)
+- Add csv lazy quote (@fredericlemoine)
+
 ### Changed in 0.12.0
 
+- series.Err is deprecated; use Error() instead
+- dataframe.Err is deprecated; use Error() instead
+
 ### Fixed in 0.12.0
 
-### Removed in 0.12.0
+- Fix dataframe.GroupBy issue (@prliu)
+- making series Order stable (@mcolosimo-p4)
 
 ## [0.11.0] - 2021-06-27
 
@@ -290,3 +298,4 @@ This document follows
 [0.10.0]:https://github.com/go-gota/gota/compare/v0.9.0...v0.10.0
 [0.10.1]:https://github.com/go-gota/gota/compare/v0.10.0...v0.10.1
 [0.11.0]:https://github.com/go-gota/gota/compare/v0.10.1...v0.11.0
+[0.12.0]:https://github.com/go-gota/gota/compare/v0.11.0...v0.12.0

dataframe/dataframe.go

@@ -34,7 +34,9 @@ type DataFrame struct {
 	columns []series.Series
 	ncols   int
 	nrows   int
-	Err     error
+
+	// deprecated: Use Error() instead
+	Err error
 }
 
 // New is the generic DataFrame constructor
@@ -103,6 +105,11 @@ func (df DataFrame) String() (str string) {
 	return df.print(true, true, true, true, 10, 70, "DataFrame")
 }
 
+// Returns error or nil if no error occured
+func (df *DataFrame) Error() error {
+	return df.Err
+}
+
 func (df DataFrame) print(
 	shortRows, shortCols, showDims, showTypes bool,
 	maxRows int,

series/series.go

@@ -20,7 +20,9 @@ type Series struct {
 	Name     string   // The name of the series
 	elements Elements // The values of the elements
 	t        Type     // The type of the series
-	Err      error    // If there are errors they are stored here
+
+	// deprecated: use Error() instead
+	Err error
 }
 
 // Elements is the interface that represents the array of elements contained on
@@ -234,6 +236,11 @@ func (s Series) Empty() Series {
 	return New([]int{}, s.t, s.Name)
 }
 
+// Returns Error or nil if no error occured
+func (s *Series) Error() error {
+	return s.Err
+}
+
 // Append adds new elements to the end of the Series. When using Append, the
 // Series is modified in place.
 func (s *Series) Append(values interface{}) {