python 中各种数据类型的排序问题

list

 #按照list的第二键值排序 disP2P = [[1,2,3],[2,3,4],[4,5,6]]
 disP2P = sorted(disP2P,key = lambda x:x[2])

 student_tuples = [
         ('john', 'A', 15),
         ('jane', 'B', 12),
         ('dave', 'B', 10),
 ]
 sorted(student_tuples, key=lambda student: student[2])   # sort by age
 [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

  class Student:
         def __init__(self, name, grade, age):
                 self.name = name
                 self.grade = grade
                 self.age = age
         def __repr__(self):
                 return repr((self.name, self.grade, self.age))
 student_objects = [
         Student('john', 'A', 15),
         Student('jane', 'B', 12),
         Student('dave', 'B', 10),
 ]
 >>> sorted(student_objects, key=lambda student: student.age)   # sort by age
 #[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

dir

 sorted(d.items(),key = lambda x:x[1],reverse = True)

多个list同时排序

 #变成元组list的形式，然后对list排序再恢复回来
 tmlist = []
         for l in range(n):
             tmlist = tmlist + [(X[l][i],y[l],w[l])]
         tmlist =sorted(tmlist,key = lambda x: x[0])
         XX = []
         W = []
         Y = []
         for l in range(n):
             XX = XX+[tmlist[l][0]]
             Y = Y + [tmlist[l][1]]
             W = W + [tmlist[l][2]]