标签：指定 生成 remove cap 速度 例子 添加 dict count
set 添加一个无序的，用set方法，访问速度快，天生解决了重复问题
1、difference 指定某个元素从原来set取出，并生成新的set
1 #difference 2 a = set(["aaa","bbb","ccc","aaa"]) 3 print(a) 4 b = a.difference(["aaa"]) 5 print(b) 6 7 {‘ccc‘, ‘bbb‘, ‘aaa‘} 8 {‘ccc‘, ‘bbb‘}
2、difference_update 删除原来set里某个元素
1 #difference_update 2 a = set(["aaa","bbb","ccc","aaa"]) 3 print(a) 4 b = a.difference_update(["aaa"]) 5 print(a) 6 print(b) 7 8 9 {‘bbb‘, ‘ccc‘, ‘aaa‘} 10 {‘bbb‘, ‘ccc‘} 11 None
3、pop 删除某个元素
1 #pop 2 a = set(["aaa","bbb","ccc","aaa"]) 3 print(a) 4 b = a.pop() 5 print(a) 6 print(b) 7 8 9 {‘aaa‘, ‘bbb‘, ‘ccc‘} 10 {‘bbb‘, ‘ccc‘} 11 aaa
4、remove 删除指定元素
1 #remove 2 a = set(["aaa","bbb","ccc","aaa"]) 3 print(a) 4 b = a.remove("ccc") 5 print(a) 6 print(b) 7 8 9 {‘bbb‘, ‘ccc‘, ‘aaa‘} 10 {‘bbb‘, ‘aaa‘} 11 None
这里举一个例子，更新、删除、添加原来的表
1 old_dict = { 2 "#1": {‘hostname‘: ‘c1‘, ‘cpu_count‘: 2, ‘mem_capicity‘: 80}, 3 "#2": {‘hostname‘: ‘c1‘, ‘cpu_count‘: 2, ‘mem_capicity‘: 80}, 4 "#3": {‘hostname‘: ‘c1‘, ‘cpu_count‘: 2, ‘mem_capicity‘: 80} 5 } 6 # cmdb 新汇报的数据 7 new_dict = { 8 "#1": {‘hostname‘: ‘c1‘, ‘cpu_count‘: 2, ‘mem_capicity‘: 800}, 9 "#3": {‘hostname‘: ‘c1‘, ‘cpu_count‘: 2, ‘mem_capicity‘: 80}, 10 "#4": {‘hostname‘: ‘c2‘, ‘cpu_count‘: 2, ‘mem_capicity‘: 80} 11 } 12 13 a = set(old_dict.keys()) 14 b = set(new_dict.keys()) 15 16 #要更新的数据 17 update_set = a.intersection(b) 18 print(update_set) 19 #要删除的数据 20 delete_set = a.symmetric_difference(update_set) 21 print(delete_set) 22 #要添加的数据 23 add_set = b.symmetric_difference(update_set) 24 print(add_set) 25 26 27 28 {‘#3‘, ‘#1‘} 29 {‘#2‘} 30 {‘#4‘}
标签：指定 生成 remove cap 速度 例子 添加 dict count
原文地址：http://www.cnblogs.com/fanyunpeng/p/6216214.html
