การแก้ไขตัวแปรนอก local scope

call_count = 0

def my_function():
  # Use a keyword that lets us update call_count 
  ____ call_count
  call_count += 1
  
  print("You've called my_function() {} times!".format(
    call_count
  ))
  
for _ in range(20):
  my_function()