Stat()IsNotExist()
package main

import (
	"os"
	"fmt"
)

func main(){
	
	filepath := "C:\\Users\\Administrator\\Desktop\\user_agent.py"
	
	_,err := os.Stat(filepath)

	if os.IsNotExist(err){
		fmt.Println("file not exist")
		return
	}

	fmt.Println("file exist")
}