An example of how python implements sorting an object list by an attribute.Share it for your reference, as follows:

For an existing python list, the content is a few objects, these objects have some same attribute values, in some specific cases, you need to choose a specific sort, that is, sort according to a specific attribute, find the following information on the Internet, generally there are two methods, but fundamentally, it is still called list.sort Method implementation.Here is a simple test code snippet:

#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)
      ]
# No. 1 Method
obj_list.sort(cmp=None, key=lambda x:x.salary, reverse=False)
print '*********** No. 1 Method ***********************'
for obj in obj_list:
  print obj.name,obj.salary
#  No. 2 Method , Better for large amounts of data .
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 '*********** No. 2 Method ***********************'
for obj in obj_list:
  print obj.name,obj.salary

Construct an Person class, then initialize some objects into obj_list, and then want to sort by wage, method 1 and method 2 achieve ascending or descending order respectively.Age ranking can also be achieved by this analogy.

The results of this example are as follows:

***********Method 1*********************** eagle 10000 sam 20000 eddy 25000 juneys 30000 ***********Method 2********************* juneys 30000 eddy 25000 sam 20000 eagle 10000

PS: Here is another presentation tool about sorting for your reference:

Online animation demonstrates the Insert/Select/Bubble/Merge/Hill/Quick Sort algorithm process tool: http://tools.ofstack.com/aideddesign/paixu\_ys

More readers interested in Python-related content can view this site’s topics: Introduction and Advanced Python Object-Oriented Programming, Python Data Structure and Algorithms, Python Function Usage Skills Summary, Python String Operation Skills Summary, Python Coding Operation Skills Summary, and Python Introduction and Advanced Classic Tutorials.

I hope that the description in this paper will be helpful to everyone’s Python program design.