python - 如何构建一个通用函数来打印 Python 3.3 中先前列表的属性列表？

Question

from collections import namedtuple
Book = namedtuple('Book', 'author title genre year price instock')

BSI = [
    Book("JK Rowling", "Harry Potter", "Fantasy", 1997, 10.00, 50),
    Book("Harper Lee", "To Kill a Mockingbird", "Fiction", 1960, 15.00, 100),
    Book("Dan Brown", "Da Vinci Code", "Thriller", 2003, 20.00, 500),
    Book("Mr. Python", "How to Python", "Technology", 2010, 40.00, 10),
    Book("Stephen King", "It", "Horror", 1986, 50.00, 10),
    Book("Some Guy", "Time Traveling", "Technology", 2020, 800.00, 256)
]

def Book_collection_attribute (BSI: list, attribute: str) -> list:
    '''Print out the list of the specific attribute of the list of Book collection'''
    for i in BSI:
        print(i.attribute)
    return BSI
    print(Book_collection_attribute(BSI,'title'))

我的目标是构建一个通用函数来打印先前列表的属性列表(在本示例中是图书列表及其属性 1:标题或流派或价格)。我可以在 Python 3.3 中执行此操作吗？

不断出现错误:

Traceback (most recent call last):
  File "C:\Users\ntt2k\Desktop\ICS 31\lab3.py", line 133, in <module>
    print(Book_collection_attribute(BSI,'title'))
  File "C:\Users\ntt2k\Desktop\ICS 31\lab3.py", line 131, in Book_collection_attribute
    print(i.attribute)
AttributeError: 'Book' object has no attribute 'attribute'

Answer 1

改变

print(i.attribute)

至

print(getattr(i, attribute)) 
#or if you want to specify a default, 
#print(getattr(i, attribute, ''))

由于attribute是一个参数，因此您需要使用getattr提取对象的属性。而不是仅仅执行i.attribute。