Classes: nested functions vs. private methodes

[Richard Lamboj]

Hello,

what should i take:
 - nested functions:
class MyClass(object)
  def blah(self):
    def blub(var1, var2):
      do something...
    blub(1, 5)

or

class MyClass(object)
  def blah(self):
    def _blub(var1, var2):
      do something...
    _blub(1, 5)

  - "private" functions:
class MyClass(object)
  def blah(self):
    self._blub()
  def _blub(self):
    do something...

What is more pythonic?

It is just for splitting up long code in classes.

Kind Regards,

Richi