问题

我有这段糟糕的代码，我试图解析一个包含字典列表的字典列表。

如果 id 匹配特定的 id，我需要输出一个包含 id 和 name 的字典列表，类似于这样：
```python
[{"id": 123}, {'name': 'bob'}]

list1 = [{"id": 123, "job": "nurse", "who":[{"user": "bob_user", "name": "bob"}]}, {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}
list2 = []
keys = ["id", "who"]

for items in list1:
  if items['id'] == 123:
    for key in keys:
      if key == "who":
        for values in items[key]:
          for count in values:
            if count == "name":
              list2.append({key : values[count]})
      else:
        list2.append({key : items[key]})

print(list2)

目前代码可以工作，但看起来像猴子写的！我该如何让它更有效率？

<details>
<summary>英文:</summary>

I have this awful awful code where I am trying to parse through a list of dictionaries which contain a list of dictionaries.

I need to output a list of dictionaries with the id and name like this if the id matches a certain id. Something like this:

[{"id": 123}, {'name': 'bob'}]

list1 = [{"id": 123, "job": "nurse", "who":[{"user": "bob_user", "name": "bob"}]}, {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}
list2 = []
keys = ["id", "who"]

for items in list1:
if items['id'] == 123:
for key in keys:
if key == "who":
for values in items[key]:
for count in values:
if count == "name":
list2.append({key : values[count]})
else:
list2.append({key : items[key]})

print(list2)

Code currently works but looks like a monkey wrote it! How can I make this more efficient?

</details>


# 答案1
**得分**: 1

How about simply accessing the element of lists and dictionaries together with slicing?

```python
list1 = [
    {"id": 123, "job": "nurse", "who":[{"user": "bob_user", "name": "bob"}]},
    {"id": 234, "job": "programmer", "who":[{"user": "alice_user", "name": "alice"}]},
    {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}
]

# Input
target_keys = ["id", "who"]
target_ids = [123, 234]

# Output
result_list = []
for item in list1:
    if item['id'] in target_ids:
        result_list.append([
            {"id": item[target_keys[0]]},
            {"name": item[target_keys[1]][0]['name']}
        ])
print(result_list)

list1 = [
    {"id": 123, "job": "nurse", "who":[{"user": "bob_user", "name": "bob"}]},
    {"id": 234, "job": "programmer", "who":[{"user": "alice_user", "name": "alice"}]},
    {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}
]

# Input
target_keys = ["id", "who"]
target_ids = [123, 234]

# Output
result_list = []
for item in list1:
    if item['id'] in target_ids:
        result_list.append([
            {"id": item[target_keys[0]]},               # {"id": item['id']},
            {"name": item[target_keys[1]][0]['name']},  # {"name": item['who'][0]['name']}
        ])
print(result_list)

答案2

得分: 1

使用Python版本：3.8或更高

list1 = [{"id": 123, "job": "nurse", "who": [{"user": "bob_user", "name": "bob"}]},
         {"id": 456, "job": "teacher", "who": [{"user": "jim_user", "name": "jim"}]}]
list2 = []
keys = ["id", "who"]
find_ids = [123, 456]

for data in list1:
    # 在检查“id”是否匹配“find_ids”列表中的id时
    # 将“id”值赋给变量“user_id”
    if (user_id := data.get("id")) in find_ids:
        user_name = data.get("who")[0].get("name")
        list2.append({"id": user_id, "who": user_name})
print(list2)
# 输出:
# [{'id': 123, 'who': 'bob'}, {'id': 456, 'who': 'jim'}]

list1 = [{"id": 123, "job": "nurse",   "who":[{"user": "bob_user", "name": "bob"}]}, 
         {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}]
list2 = []
keys = ["id", "who"]
find_ids = [123, 456]

for data in list1:
    # while checking if the "id" matches list of ids in "find_ids"
    # We are assigning the "id" value to variable "user_id"
    if (user_id:=data.get("id")) in find_ids:
        user_name = data.get("who")[0].get("name")
        list2.append({"id": user_id, "who": user_name})
print(list2)
# output:
# [{'id': 123, 'who': 'bob'}, {'id': 456, 'who': 'jim'}]

答案3

得分: 1

你可以使用Pythonic列表推导式将这段代码简化为一行。根据@Jiho Choi的示例，假设输入是多个目标ID，并且假设"who"键的数组值只包含一个字典项，这将是最简洁的解决方案：

list1 = [
        {"id": 123, "job": "nurse", "who":[{"user": "bob_user", "name": "bob"}]},
        {"id": 234, "job": "programmer", "who":[{"user": "alice_user", "name": "alice"}]},
        {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}
        ]
# 输入
target_ids = [123, 234]

# 输出
result_list = [{"id": x["id"], "who": x["who"][0]["name"]} for x in list1 if x["id"] in target_ids]
print(result_list)

list1 = [
        {"id": 123, "job": "nurse", "who":[{"user": "bob_user", "name": "bob"}]},
        {"id": 234, "job": "programmer", "who":[{"user": "alice_user", "name": "alice"}]},
        {"id": 456, "job": "teacher", "who":[{"user": "jim_user", "name": "jim"}]}
        ]
# Input
target_ids = [123, 234]

# Output
result_list = [[{'id': x['id']}, {'who': x['who'][0]['name']}] for x in list1 if x['id'] in target_ids]
print(result_list)