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【学习笔记】《Python编程从入门到实践》第3章：Python列表完全指南——创建、修改、删除与排序

news 2026/5/26 22:13:30

【学习笔记】《Python编程从入门到实践》第3章：Python列表完全指南——创建、修改、删除与排序

第3章列表简介

本章目标：理解列表的概念，掌握创建、访问、修改、删除列表元素的方法，学会组织列表的常用操作。

3.1 列表是什么

列表由一系列按特定顺序排列的元素组成。用方括号 [] 表示，逗号分隔元素。

bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles)
# ['trek', 'cannondale', 'redline', 'specialized']

建议给列表指定复数名称，如 letters、digits、names。

3.1.1 访问列表元素

通过索引（从 0 开始）访问：

bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles[0])                 # trek
print(bicycles[0].title())         # Trek（可对元素调用字符串方法）

3.1.2 索引从 0 而不是 1 开始

bicycles = ['trek', 'cannondale', 'redline', 'specialized']
print(bicycles[1])     # cannondale（第二个元素）
print(bicycles[3])     # specialized（第四个元素）
负索引：-1 表示最后一个元素
print(bicycles[-1])    # specialized

print(bicycles[-2])    # redline（倒数第二个）

print(bicycles[-3])    # cannondale

3.1.3 使用列表中的各个值

bicycles = ['trek', 'cannondale', 'redline', 'specialized']
message = "My first bicycle was a " + bicycles[0].title() + "."
print(message)
# My first bicycle was a Trek.

3.2 修改、添加和删除元素

3.2.1 修改列表元素

直接通过索引赋值：

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles[0] = 'ducati'
print(motorcycles)
# ['ducati', 'yamaha', 'suzuki']

3.2.2 在列表中添加元素

append() — 在末尾添加：

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.append('ducati')
print(motorcycles)
# ['honda', 'yamaha', 'suzuki', 'ducati']
常用模式：先建空列表，再 append
motorcycles = []

motorcycles.append('honda')

motorcycles.append('yamaha')

motorcycles.append('suzuki')

print(motorcycles)
['honda', 'yamaha', 'suzuki']

insert() — 在任意位置插入（指定索引和值）：

motorcycles = ['honda', 'yamaha', 'suzuki']
motorcycles.insert(0, 'ducati')
print(motorcycles)
# ['ducati', 'honda', 'yamaha', 'suzuki']

insert(0, 'ducati') 在索引 0 处插入，原有元素右移。

3.2.3 从列表中删除元素

方法	用法	特点
`del`	`del list[index]`	删除后无法再访问该值
`pop()`	`list.pop()`	删除末尾元素并返回该值
`pop(index)`	`list.pop(index)`	删除任意位置元素并返回
`remove()`	`list.remove(value)`	按值删除第一个匹配项

del 语句 — 按位置删除（不再需要该值）：

motorcycles = ['honda', 'yamaha', 'suzuki']
del motorcycles[0]
print(motorcycles)
# ['yamaha', 'suzuki']
del motorcycles[1]

print(motorcycles)
['honda', 'suzuki']

pop() 方法 — 删除并继续使用该值：

# 默认弹出末尾
motorcycles = ['honda', 'yamaha', 'suzuki']
popped_motorcycle = motorcycles.pop()
print(motorcycles)           # ['honda', 'yamaha']
print(popped_motorcycle)     # suzuki
使用弹出的值
last_owned = motorcycles.pop()

print("The last motorcycle I owned was a " + last_owned.title() + ".")

pop(index) — 弹出任意位置：

motorcycles = ['honda', 'yamaha', 'suzuki']
first_owned = motorcycles.pop(0)
print('The first motorcycle I owned was a ' + first_owned.title() + '.')
# The first motorcycle I owned was a Honda.

判断标准：

删除后不再使用 → del
删除后还要使用 → pop()

remove() — 按值删除（只删第一个匹配项）：

motorcycles = ['honda', 'yamaha', 'suzuki', 'ducati']
motorcycles.remove('ducati')
print(motorcycles)
# ['honda', 'yamaha', 'suzuki']
可先用变量存储，删除后继续使用该值
too_expensive = 'ducati'

motorcycles.remove(too_expensive)

print("\nA " + too_expensive.title() + " is too expensive for me.")
A Ducati is too expensive for me.

⚠️ remove() 只删除第一个匹配值。多个重复值需要用循环处理（第 7 章）。

3.3 组织列表

3.3.1 `sort()` — 永久排序

cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.sort()
print(cars)
# ['audi', 'bmw', 'subaru', 'toyota']
倒序排列
cars.sort(reverse=True)

print(cars)
['toyota', 'subaru', 'bmw', 'audi']

sort() 永久修改列表顺序，不可恢复。

3.3.2 `sorted()` — 临时排序

cars = ['bmw', 'audi', 'toyota', 'subaru']
print("Here is the original list:")
print(cars)
print("\nHere is the sorted list:")

print(sorted(cars))
print("\nHere is the original list again:")

print(cars)
倒序临时排序
print(sorted(cars, reverse=True))

sorted() 返回排序后的副本，不修改原列表。

3.3.3 `reverse()` — 反转列表

cars = ['bmw', 'audi', 'toyota', 'subaru']
cars.reverse()
print(cars)
# ['subaru', 'toyota', 'audi', 'bmw']

reverse() 永久反转顺序，再次调用可恢复。

3.3.4 `len()` — 获取列表长度

>>> cars = ['bmw', 'audi', 'toyota', 'subaru']
>>> len(cars)
4

3.4 使用列表时避免索引错误

IndexError: list index out of range — 索引超出列表范围：

motorcycles = ['honda', 'yamaha', 'suzuki']
print(motorcycles[3])    # ❌ IndexError（只有索引 0, 1, 2）

解决方法：

尝试将索引减 1
使用 -1 访问最后一个元素（仅在列表非空时有效）
将列表或其长度打印出来，查看实际内容

# 空列表使用 -1 也会出错
motorcycles = []
print(motorcycles[-1])   # ❌ IndexError

动手试一试

3-1 姓名

names = ['Alice', 'Bob', 'Charlie']
print(names[0])
print(names[1])
print(names[2])

3-2 问候语

names = ['Alice', 'Bob', 'Charlie']
print("Hello, " + names[0] + "!")
print("Hello, " + names[1] + "!")
print("Hello, " + names[2] + "!")

3-3 自己的列表

commute = ['motorcycle', 'car', 'bike']
print("I would like to own a Honda " + commute[0] + ".")

3-4 ~ 3-7 嘉宾名单系列

# 3-4 嘉宾名单
guests = ['Einstein', 'Mozart', 'Curie']
print("Dear " + guests[0] + ", please join me for dinner.")
print("Dear " + guests[1] + ", please join me for dinner.")
print("Dear " + guests[2] + ", please join me for dinner.")
3-5 修改嘉宾名单
print("\n" + guests[1] + " can't make it.")

guests[1] = 'Newton'

print("Dear " + guests[0] + ", please join me for dinner.")

print("Dear " + guests[1] + ", please join me for dinner.")

print("Dear " + guests[2] + ", please join me for dinner.")
3-6 添加嘉宾
print("\nI found a bigger table!")

guests.insert(0, 'Da Vinci')

guests.insert(2, 'Shakespeare')

guests.append('Tesla')

print("Dear " + guests[0] + ", please join me for dinner.")

print("Dear " + guests[1] + ", please join me for dinner.")

print("Dear " + guests[2] + ", please join me for dinner.")

print("Dear " + guests[3] + ", please join me for dinner.")

print("Dear " + guests[4] + ", please join me for dinner.")

print("Dear " + guests[5] + ", please join me for dinner.")
3-7 缩减名单
print("\nSorry, I can only invite two people for dinner.")

popped = guests.pop()

print("Sorry " + popped + ", I can't invite you to dinner.")

popped = guests.pop()

print("Sorry " + popped + ", I can't invite you to dinner.")

popped = guests.pop()

print("Sorry " + popped + ", I can't invite you to dinner.")

popped = guests.pop()

print("Sorry " + popped + ", I can't invite you to dinner.")

print("\nDear " + guests[0] + ", you're still invited.")

print("Dear " + guests[1] + ", you're still invited.")

del guests[0]

del guests[0]

print(guests)   # []

3-8 放眼世界

places = ['Tokyo', 'Iceland', 'New Zealand', 'Egypt', 'Brazil']
print(places)
print(sorted(places))
print(places)
print(sorted(places, reverse=True))
print(places)
places.reverse()
print(places)
places.reverse()
print(places)
places.sort()
print(places)
places.sort(reverse=True)
print(places)

3-9 晚餐嘉宾

guests = ['Einstein', 'Mozart', 'Curie', 'Newton', 'Da Vinci']
print("I invited " + str(len(guests)) + " guests to dinner.")

3-10 尝试使用各个函数

languages = ['Python', 'Java', 'C', 'JavaScript', 'Ruby']
print(languages)
print(sorted(languages))
languages.sort()
print(languages)
languages.sort(reverse=True)
print(languages)
languages.reverse()
print(languages)
print(len(languages))
languages.append('Go')
languages.insert(0, 'Swift')
print(languages)
languages.pop()
languages.remove('Swift')
print(languages)

3-11 有意引发错误

items = [1, 2, 3]
# print(items[3])   # ❌ IndexError
print(items[-1])    # ✅ 使用 -1 安全访问最后一个

代码块汇总

# 创建列表
bicycles = ['trek', 'cannondale', 'redline', 'specialized']
访问元素（索引从 0 开始）
bicycles[0]           # 第一个元素

bicycles[-1]          # 最后一个元素
修改
motorcycles[0] = 'ducati'
添加
motorcycles.append('ducati')     # 末尾

motorcycles.insert(0, 'ducati')  # 指定位置
删除
del motorcycles[0]               # 按索引删除（不使用值）

popped = motorcycles.pop()       # 弹出末尾（使用值）

popped = motorcycles.pop(0)      # 弹出任意位置

motorcycles.remove('ducati')     # 按值删除（只删第一个）
排序
cars.sort()                      # 永久排序

cars.sort(reverse=True)          # 永久倒序

sorted(cars)                     # 临时排序

sorted(cars, reverse=True)       # 临时倒序
反转
cars.reverse()
长度
len(cars)

常见错误 / 陷阱

错误类型	说明	解决
`IndexError`	索引超出范围	索引从 0 开始，最大索引为 `len(list) - 1`
空列表 `-1`	空列表用 `-1` 也会出错	访问前检查列表是否为空
`remove()` 只删一个	重复值只删第一个	用循环处理
误用 `sort()`	以为 `sort()` 不影响原列表	`sort()` 永久修改，`sorted()` 临时修改