package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)customers(?=(?:[^><]*<[^<>]*>)*[^><]*$)`)
var str = `<p class="Pa0" style="margin: 0in 0in 0pt;"><span class="A1"><span style="font-size: 10pt;">Giving this flyer to your class customers</span></span></p>
`
var substitution = "<span style='color: red;'>class<span>"
fmt.Println(re.ReplaceAllString(str, substitution))
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/