title: How do I know the total length of the data read from a CSV file?
body: <p>How do I know the total length of the data read from a CSV file ?</p>
  
  <pre><code>func main(){
  
  openfile, _ := os.Open(filepath)
  
          //read the data of file
          filedata, _ := csv.NewReader(openfile).ReadAll()
  
          for e, value := range filedata {
  
               // what should I write here for getting the total length of the data?
  
          }
  }
  </code></pre>