python实现对象列表根据某个属性排序的方法详解

#coding:utf-8
class Person:
  def __init__(self,name,age,salary):
    self.name = name
    self.age = age
    self.salary = salary
obj_list = [
      Person('juneys',20,30000),
      Person('sam',20,20000),
      Person('eddy',22,25000),
      Person('eagle',25,10000)
      ]
#第一种方法
obj_list.sort(cmp=None, key=lambda x:x.salary, reverse=False)
print '***********第一种方法***********************'
for obj in obj_list:
  print obj.name,obj.salary
# 第二种方法,更适合于大量数据的情况.
try:
  import operator
except ImportError:
  cmpfun= lambda x: x.count # use a lambda if no operator module
else:
  cmpfun= operator.attrgetter("salary") # use operator since it's faster than lambda
obj_list.sort(key=cmpfun, reverse=True)
print '***********第二种方法***********************'
for obj in obj_list:
  print obj.name,obj.salary