title: Max() from a CSV column: ValueError: max() arg is an empty sequence
body: <p><strong>I am trying to open a csv and then us the columns to find totals and averages but I keep getting a value error when attempting to return the max height</strong></p>
  <pre><code>with open('athlete_events_short.csv', 'r', newline='') as athletes:
      reader = csv.reader(athletes)
      header = next(reader)
      
      
      for line in reader:
          new_athlete = Athlete(line[1], line[2], line[3], line[4], line[5], line[6], 
              line[7], line[8], line[9], line[10], line[11], line[12], line[13], line[14])
          athlete_list.append(new_athlete)
          
      
          
      for athlete in athlete_list:
          age_total += athlete.get_age()
          weight_total += athlete.get_weight()
          height_total += athlete.get_height()
          max_height = max(reader, key=lambda column: (column[5].replace(',',''))) # this works but it returns a letter..not the max number
  
  print(f'Average age in years for all olympians = {age_total/len(athlete_list):.2f}')
  print(f'Average weight for all olympians = {weight_total/len(athlete_list):.2f} kilograms')
  print(f'Average height for all olympians = {height_total/len(athlete_list):.2f} centimeters')
  print(f'The tallest of all olympians is = {max_height:.2f} centimeters') # I can not get this to work.
  </code></pre>