单独访问嵌套在字典中列表中的元素

Question

我想访问公司名单中的数据，这是在字典中，实际上是一个列表。在运行这段代码时，我得到了"TypeError:列表索引必须是整数或片“。J循环接受项目中的第一个列表，并使用它进行迭代，直到“companies”中的每个元素都被覆盖为止，但是我不明白为什么它不能工作。任何建议都会很有帮助

l= [{ "id":"a","name":"rocky","companies": ["1","2","3"], "data":"", "data2": {"x","y"} },
    {"id":"b","name":"duster","companies": ["4","5","6"], "data":"", "data2": {"h","p"} } ]


for i in l:
    name=i['name']
    id=i['id']
    for j in l[i]['companies']:
        cmp= j

Output:
id name companies
a   rocky 1
a   rocky 2
a   rocky 3
b   rocky 4
b   duster 5
b   duster 6 

Answer 1

您正在尝试使用列表项而不是索引来索引您的循环。例如，使用这个：

for idx, i in enumerate(l):
    name=i['name']
    id=i['id']
    for j in l[idx]['companies']:
        cmp= j

现在，idx是索引列表"l“所需的整数。

Answer 2

此错误是因为您正在使用列表中的项，如索引for j in l[i]['companies']。这里，i不是索引，而是项本身。

您可以通过使用i来获得类似于for j in i['companies']的companies来修复它。

获得结果的另一种方法是使用list-comprehension和itemgetter

from operator import itemgetter

items = [itemgetter('id', 'name', 'companies')(x) for x in l]
result = [tuple(zip([a]*len(c), [b]*len(c), c)) for a, b, c in items]

Answer 3

代码中有两个问题。第一个输入list。第二，代码中的语法错误。

for i in l:
    name=i['name']
    id=i['id']
    for j in l[i]['companies']:
        cmp= j

在这里，i本身就是一个字典，您不能将它用于解析list l和inner for lop l[i]['companies']。这就是您获得错误的原因："TypeError: list indices must be integers or slices"

l**:** 校正输入列表

l = [{ "id":"a","name":"rocky","companies": ["1","2","3"], "data":"", "data2": {"x","y"}} ,{"id":"b","name":"duster","companies": ["4","5","6"], "data":"", "data2": {"h","p"} } ]

修改代码

count = 0
print("id name companies")
for i in l:
    name=i['name']
    id=i['id']
    #print(l[count])
    for j in l[count].get("companies"):
        cmp = j
        print("{}  {}  {}".format(id, name, cmp))
    count += 1

输出

id name companies
a  rocky  1
a  rocky  2
a  rocky  3
b  duster  4
b  duster  5
b  duster  6