Compare CSV and conclusion of differences - csv

Question

I started writing a program to compare two CSV files. After reading the documentation, I found a solution for I can't figure out how to print the differences from the second file since the function returns true/false
package main
import (
"encoding/csv"
"fmt"
"os"
"reflect"
)
func main() {
file, err := os.Open("sms_in_max.csv")
if err != nil {
fmt.Println(err)
}
reader := csv.NewReader(file)
records, _ := reader.ReadAll()
fmt.Println(records)
file2, err := os.Open("sms_out.csv")
if err != nil {
fmt.Println(err)
}
reader2 := csv.NewReader(file2)
records2, _ := reader2.ReadAll()
fmt.Println(records2)
allrs :=reflect.DeepEqual(records, records2)
fmt.Println(allrs)
}

Answer 1

The csv ReadAll() function returns slice of rows, where row is a slice of columns.
We can loop over the rows, and within a row, again loop over the columns and compare each column value.
Here is the code that prints all lines that have differences alongwith their line numbers.
package main
import (
"encoding/csv"
"fmt"
"os"
)
func main() {
file, err := os.Open("sms_in_max.csv")
if err != nil {
fmt.Println(err)
}
reader := csv.NewReader(file)
records, _ := reader.ReadAll()
fmt.Println(records)
file2, err := os.Open("sms_out.csv")
if err != nil {
fmt.Println(err)
}
reader2 := csv.NewReader(file2)
records2, _ := reader2.ReadAll()
fmt.Println(records2)
// allrs := reflect.DeepEqual(records, records2)
// fmt.Println(allrs)
// Prints lines at which there is difference
for i := range records {
diff := false
for j := range records[i] {
if records[i][j] != records2[i][j] {
diff = true
break
}
}
if diff {
fmt.Printf("Line %d: %v, %v\n", i+1, records[i], records2[i])
}
}
}