比较运算符

• lt(a, b) - 小于
• le(a, b) - 小于等于
• eq(a, b) - 等于
• ne(a, b) - 不等于
• ge(a, b) - 大于等于
• gt(a, b) - 大于

算术运算符

• add(a, b) - 加法
• sub(a, b) - 减法
• mul(a, b) - 乘法
• truediv(a, b) - 除法
• floordiv(a, b) - 整除
• mod(a, b) - 取模

逻辑运算符

• not_(obj) - 非运算
• truth(obj) - 真值测试
• is_(a, b) - 对象标识
• is_not(a, b) - 非对象标识

序列操作

• concat(seq1, seq2) - 连接序列
• contains(seq, obj) - 包含测试
• countOf(seq, obj) - 计数
• getitem(seq, index) - 获取元素

import operator

# 创建用户列表
users = [
    {'name': 'Alice', 'age': 30, 'join_date': '2020-05-15'},
    {'name': 'Bob', 'age': 25, 'join_date': '2019-11-03'},
    {'name': 'Charlie', 'age': 35, 'join_date': '2021-01-22'}
]

# 按年龄排序
users_by_age = sorted(users, key=operator.itemgetter('age'))
print("按年龄排序:", [user['name'] for user in users_by_age])

# 按加入日期排序
users_by_date = sorted(users, key=operator.itemgetter('join_date'))
print("按加入日期排序:", [user['name'] for user in users_by_date])

# 按多个字段排序
users_by_age_name = sorted(users, key=operator.itemgetter('age', 'name'))
print("按年龄和姓名排序:", [user['name'] for user in users_by_age_name])

import operator

# 使用operator替代lambda
numbers = [5, 2, 8, 1, 9, 3]

# 使用lambda获取最大值
max_lambda = max(numbers, key=lambda x: x)

# 使用operator获取最大值
max_operator = max(numbers, key=operator.itemgetter(0))

print(f"使用lambda: {max_lambda}, 使用operator: {max_operator}")

# 计算乘积
product = 1
for num in numbers:
    product = operator.mul(product, num)
    
print("列表乘积:", product)

# 属性获取器
class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

people = [Person('Alice', 30), Person('Bob', 25), Person('Charlie', 35)]
names = list(map(operator.attrgetter('name'), people))
ages = list(map(operator.attrgetter('age'), people))

print("姓名列表:", names)
print("年龄列表:", ages)

import operator
from functools import reduce

# 计算阶乘
n = 5
factorial = reduce(operator.mul, range(1, n+1))
print(f"{n}的阶乘是: {factorial}")

# 点积计算
vector1 = [2, 3, 5]
vector2 = [4, 2, 1]
dot_product = sum(map(operator.mul, vector1, vector2))
print(f"点积结果: {dot_product}")

# 条件过滤
numbers = [12, 7, 18, 5, 9, 21, 14]
greater_than_10 = list(filter(operator.methodcaller('__gt__', 10), numbers))
print("大于10的数字:", greater_than_10)

# 使用itemgetter处理元组列表
data = [('apple', 3), ('banana', 2), ('orange', 5), ('kiwi', 1)]
sorted_data = sorted(data, key=operator.itemgetter(1))
print("按数量排序:", sorted_data)

lambda表达式

sorted(data, key=lambda x: x[1])

执行时间: ~1.2μs

operator函数

sorted(data, key=operator.itemgetter(1))

执行时间: ~0.8μs