self

class Staff(object):
   def __init__(self, name, age):
      self.name = name
      self.age = age
   def printInfo(self):
      print '%s is %r-years-old.' % (self.name, self.age)

staff1 = Staff('helen', 24)
staff2 = Staff('ply', 25)
staff1.printInfo()
staff2.printInfo()

# 运行结果
helen is 24-years-old.
ply is 25-years-old.

结论：self 不需要传，Python 解释器自己会把实例变量传进去。