問(wèn)題描述

有1個(gè)有序日期列表A[’2016-01-01’,’2016-01-02’,’2016-01-03’,....’2017-06-01’]和1個(gè)無(wú)序的但是是需要排除的日期的列表B[’2016-03-02’,’2016-03-08’,]希望把A中的包含的B元素全部去除掉，下面的寫(xiě)法可有不妥？

for x in B: A.remove(x)

問(wèn)題解答

A = [item for item in A if item not in set(B)]回答2：

a = [’2016-01-01’,’2016-01-02’,’2016-01-03’,’2017-06-01’, ’2016-03-08’]b = [’2016-03-02’,’2016-03-08’,]print set(a) - set(b)回答3：

看你需求吧,沒(méi)啥毛病,數(shù)據(jù)也不是很多, 我提供一種方案

from collections import OrderedDictd_set = OrderedDict.fromkeys(A)for x in B: del d_set[x]A = d_set.keys()回答4：

這種寫(xiě)法會(huì)報(bào)錯(cuò),如果x 不在A 中就會(huì)報(bào)錯(cuò),這種寫(xiě)法可以先加個(gè) if 判斷, x 是否在 A 中再執(zhí)行 A.remove(x)

試試這個(gè)簡(jiǎn)單的寫(xiě)法:

#coding=utf-8A = [’2016-01-01’,’2016-01-02’,’2016-01-03’,’2017-06-01’,’2017-06-01’,’2016-03-08’,’2016-03-08’]B = [’2016-03-02’,’2016-03-08’]C = []for a in A: for b in B:if a == b: break else:C.append(a)print C回答5：

from collections import OrderedDictA = [’2016-01-01’,’2016-01-02’,’2016-01-03’,’2017-06-01’,’2016-03-08’]B = [’2016-03-02’,’2016-03-08’]d_set = OrderedDict.fromkeys(A)for x in B:

if x in A: del d_set[x]

A = d_set.keys()