python 字典的用法

1. 创建一个空字典

dict = {}

2. 判断字典中有无目标索引

if a in dict

3. 字典中索引的值加一

dict['a'] = dict.get('a', 0) + 1

4. 将字典写入csv文件

writer = csv.writer(csvfile)
for key, value in dict.items():
    writer.writerow([key, value])

5. 当字典的value是一个list时候

if name not in task:
    task[name] = []

 往list里增加数据

exit = {}
exit.setdefault(col[0],[]).append(col[1])

如果两个字典有相同索引，继续比较其list中有无交集

for i in exit.keys():
    for j in exithis.keys():
        if j == i:
            result = list(set(exit[i]).intersection(set(exithis[j])))
            if result:
                print(i)
                print(result)