Having an object array in python, how can I classify its elements by an attribute?
在python中，是否有一个按属性对对象数组进行分类和排序的函数？
例子：
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | class Book: """A Book class""" def __init__(self,name,author,year): self.name = name self.author = author self.year = year hp1 = Book("Harry Potter and the Philosopher's stone","J.k Rowling",1997) hp2 = Book("Harry Potter and the chamber of secretse","J.k Rowling",1998) hp3 = Book("Harry Potter and the Prisioner of Azkaban","J.k Rowling",1999) #asoiaf stands for A Song of Ice and Fire asoiaf1 = Book("A Game of Thrones","George R.R Martin",1996) asoiaf2 = Book("A Clash of Kings","George R.R Martin",1998) hg1 = Book("The Hunger Games","Suzanne Collins",2008) hg2 = Book("Catching Fire","Suzanne Collins",2009) hg3 = Book("Mockingjaye","Suzanne Collins",2010); books = [hp3,asoiaf1,hp1,hg1,hg2,hp2,asoiaf2,hg3] #disordered on purpose organized_by_autor = magic_organize_function(books,"author") |
魔法组织功能是否存在？否则，会是什么？
按作者排序是一种方法：
1 2 3 | sorted_by_author = sorted(books, key=lambda x: x.author) for book in sorted_by_author: print(book.author) |
输出：
1 2 3 4 5 6 7 8 | George R.R Martin George R.R Martin J.k Rowling J.k Rowling J.k Rowling Suzanne Collins Suzanne Collins Suzanne Collins |
号
您还可以使用
1 2 3 4 5 6 7 8 | from itertools import groupby organized_by_author = groupby(sorted_by_author, key=lambda x: x.author) for author, book_from_author in organized_by_author: print(author) for book in book_from_author: print(' ', book.name) |
输出：
1 2 3 4 5 6 7 8 9 10 11 | George R.R Martin A Game of Thrones A Clash of Kings J.k Rowling Harry Potter and the Prisioner of Azkaban Harry Potter and the Philosopher's stone Harry Potter and the chamber of secretse Suzanne Collins The Hunger Games Catching Fire Mockingjaye |
。
注：您需要将排序后的