python：匿名函数

1、匿名函数 语法格式lambda 参数列表: 表达式 funclambdax1,x2:x1*x2print(func(2,2))# 结果4# sorted排序print(sorted排序)list_demo1[{name:张三,age:20,index:3},{name:李四,age:22,index:2},{name:王五,age:18,index:1}]# 年龄由大到小排序list_demo2sorted(list_demo1,keylambdaitem:item[age],reverseTrue)print(list_demo2)# 结果# [{name: 李四, age: 22, index: 2}, {name: 张三, age: 20, index: 3}, {name: 王五, age: 18, index: 1}]# filter过滤print(filter过滤)list_filter1[{name:张三,age:20,index:10},{name:李四,age:22,index:2},{name:王五,age:18,index:8},{name:马六,age:16,index:6},{name:小七,age:15,index:1}]# 过滤age 18index 5list_filter2list(filter(lambdaitem:item[age]18anditem[index]5,list_filter1))print(list_filter2)# 结果# [{name: 王五, age: 18, index: 8}, {name: 马六, age: 16, index: 6}]# mapprint(map)list_map1[{name:张三,age:20,index:3},{name:李四,age:22,index:2},{name:王五,age:18,index:1}]list_map2map(lambdaitem:(item[name],item),list_map1)map_resultdict(list_map2)print(map_result)# 结果# {张三: {name: 张三, age: 20, index: 3}, 李四: {name: 李四, age: 22, index: 2}, 王五: {name: 王五, age: 18, index: 1}}结果4sorted排序[{‘name’: ‘李四’, ‘age’: 22, ‘index’: 2}, {‘name’: ‘张三’, ‘age’: 20, ‘index’: 3}, {‘name’: ‘王五’, ‘age’: 18, ‘index’: 1}]filter过滤[{‘name’: ‘王五’, ‘age’: 18, ‘index’: 8}, {‘name’: ‘马六’, ‘age’: 16, ‘index’: 6}]map{‘张三’: {‘name’: ‘张三’, ‘age’: 20, ‘index’: 3}, ‘李四’: {‘name’: ‘李四’, ‘age’: 22, ‘index’: 2}, ‘王五’: {‘name’: ‘王五’, ‘age’: 18, ‘index’: 1}}