Python中collections.namedtuple用法

namedtuple可用于创建一个命名元组类

官方文档:collections --- 容器数据类型 — Python 3.12.0 文档

简单示例:

from collections import namedtuple

# 创建一个命名元组类
Person = namedtuple('Person', 'name age gender')

# 使用 _make() 方法将序列转换为命名元组
person_data = ['John', '25', 'Male']
person = Person._make(person_data)

# 输出命名元组的属性值
print(person.name)    # John
print(person.age)     # 25
print(person.gender)  # Male

上面提示到_make()方法,该方法用于将一个可迭代对象转换为命名元组,常用于将csv sqlite3模块返回的数据转化为命名元组:

# 创建一个命名元组类
EmployeeRecord = namedtuple('EmployeeRecord', 'name, age, title, department, paygrade')

import csv

# 将获取到的csv数据,转化为命名元组(n个 EmployeeRecord 对象组成)
for emp in map(EmployeeRecord._make, csv.reader(open("employees.csv", "rb"))):
    print(emp.name, emp.title)

import sqlite3
conn = sqlite3.connect('/companydata')
cursor = conn.cursor()
cursor.execute('SELECT name, age, title, department, paygrade FROM employees')
for emp in map(EmployeeRecord._make, cursor.fetchall()):
    print(emp.name, emp.title)