刘心向学（43）：namedtuple — 给元组起个名字

摘要：Python深色版本defget_user_info:return"Bob", 30, "Teacher"# 返回一个元组name, age, job = get_user_infoprint(f"{name} is {age} years old.") #

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“刘心向学（43）：namedtuple — 给元组起个名字”

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“Liu Xin Xiang Xue (43): namedtuple — Giving Tuples a Name”

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Python深色版本defget_user_info:return"Bob", 30, "Teacher"# 返回一个元组name, age, job = get_user_infoprint(f"{name} is {age} years old.") # 必须记住顺序

但如果返回值顺序变了，或者你记错了索引，程序就会出错。

But if the return order changes, or you misremember the index, your program will break.

With namedtuple, you can write:

Python深色版本from collections import namedtupleUser = namedtuple('User', ['name', 'age', 'job'])user = User('Bob', 30, 'Teacher')print(f"{user.name} is {user.age} years old.") # 清晰、安全

字段名让数据“有身份”，代码瞬间变得可读又健壮。

Field names give data an "identity", instantly making your code more readable and robust.

namedtuple is a factory function in the collections module used to create named tuple classes.

它生成的类：

The generated class:

继承自 tuple，因此不可变、可哈希、可作为字典键Inherits from tuple, so it is immutable, hashable, and can be used as a dictionary key支持通过字段名访问元素（如 obj.name）Supports access by field name (e.g., obj.name)支持索引和切片（如 obj[0]）Supports indexing and slicing (e.g., obj[0])内存占用小，性能高

Has low memory footprint and high performance

一句话：它是“带名字的元组”，是轻量级数据容器的理想选择。

Python深色版本from collections import namedtuple# 方法1：字段名用字符串（空格或逗号分隔）Point = namedtuple('Point', 'x y')# 方法2：字段名用列表Person = namedtuple('Person', ['name', 'age', 'job'])Python深色版本p = Point(3, 4)print(p.x, p.y) # 3 4print(p[0], p[1]) # 3 4print(len(p)) # 2# 拆包依然有效x, y = pPython深色版本# 从可迭代对象创建data = ['Alice', 28, 'Designer']person = Person._make(data)# 转为有序字典print(person._asdict)# OrderedDict([('name', 'Alice'), ('age', 28), ('job', 'Designer')])# 创建新实例（不可变）new_person = person._replace(age=29)print(new_person) # Person(name='Alice', age=29, job='Designer')# 查看字段名print(Person._fields) # ('name', 'age', 'job')Python深色版本Car = namedtuple('Car', ['brand', 'model', 'year'], defaults=[2020, 'Unknown'])car = Car('Tesla', 'Model 3')print(car) # Car(brand='Tesla', model='Model 3', year=2020)Python深色版本defget_stats(data):return namedtuple('Stats', 'mean median std')( mean=sum(data)/len(data), median=sorted(data)[len(data)//2], std=1.0# 简化 )result = get_stats([1,2,3,4,5])print(result.mean, result.std) # 3.0 1.0Python深色版本import csvfrom collections import namedtupleRow = namedtuple('Row', 'id,name,email')withopen('users.csv') as f: reader = csv.reader(f)for row inmap(Row._make, reader):print(f"Processing {row.name}")Python深色版本Config = namedtuple('Config', 'host port timeout')config = Config('localhost', 8080, 30)# 使用时清晰明确server.start(config.host, config.port)Python深色版本Color = namedtuple('Color', 'red green blue')RED = Color(255, 0, 0)GREEN = Color(0, 255, 0)print(RED.red) # 255六、与 typing.NamedTuple（推荐用于新项目）（With typing.NamedTuple (Recommended for New Projects)）

Python 3.6+ 引入了 typing.NamedTuple，支持类型提示，更现代：

Python 3.6+ introduced typing.NamedTuple, which supports type hints and is more modern:

Python深色版本from typing import NamedTupleclassEmployee(NamedTuple): name: str age: int salary: float = 50000.0# 支持默认值emp = Employee("Charlie", 35)print(emp.salary) # 50000.0

建议：新项目优先使用 typing.NamedTuple，旧项目可用 collections.namedtuple。

Recommendation:Use typing.NamedTuple in new projects; use collections.namedtuple in legacy code.

Immutability和元组一样，namedtuple实例一旦创建就不能修改。需要修改时使用 _replace创建新实例。

Like tuples, namedtuple instances cannot be modified after creation. Use _replace to create a new instance when changes are needed.

不适合频繁修改的场景

如果数据需要频繁更新，考虑使用 dataclass 或普通类。

If data needs frequent updates, consider using dataclass or a regular class.

字段名不能是 Python 关键字或以 _ 开头

rename=True 自动重命名冲突字段。

If needed, set rename=True to automatically rename conflicting fields.

namedtuple 是 Python 标准库中一个“小而美”的工具。它用极低的性能开销，为元组带来了可读性、安全性与表达力。

namedtuple

is a "small but beautiful" tool in Python’s standard library. With minimal performance overhead, it brings readability, safety, and expressiveness to tuples.

它不是要取代类或字典，而是填补了一个关键空白：当你需要一个不可变、轻量、命名清晰的数据结构时。

It's not meant to replace classes or dictionaries, but fills a crucial gap:

“Readability counts.”
“Simple is better than complex.”

而 namedtuple，正是这一哲学的完美体现。

namedtuple

is a perfect embodiment of these principles.

下次当你写下 return x, y, z 时，不妨问自己：

“这三个值，有没有名字？”

Next time you write return x, y, z, ask yourself:

“Do these three values have names?”

如果有，那就用 namedtuple 给它们一个身份。

If they do, give them an identity with namedtuple.