Python Object Oriented - Data Hiding

• #!/usr/bin/python
  
  class JustCounter:
     __secretCount = 0
  
     def count(self):
       self.__secretCount += 1
       print self.__secretCount
  
  counter = JustCounter()
  counter.count()
  counter.count()
  print counter.__secretCount

• Output

  1
  2
  Traceback (most recent call last):
  File "test.py", line 12, in < module >
  print counter.__secretCount
  AttributeError: JustCounter instance has no attribute '__secretCount'
• Python protects those members by internally changing the name to include the class name. You can access such attributes as object._className__attrName. If you would replace your last line as following, then it would work for you:
  
  .........................
  print counter._JustCounter__secretCount

  Output

  1
  2
  2