如何遍历包含字典的列表？

Question

我正在尝试遍历 JSON 数据并放入 Dataframe。

这里是用来导入数据的代码：

df = json_normalize(data['PatentBulkData'])

Dataframe的每个系列都是一个列表。每个列表包含一个字典列表，如下所示。

例如，这是我输入 df['prosecutionHistoryDataBag.prosecutionHistoryData'][i] 时 return 编辑的词典列表：

[{'eventCode': 'PG-ISSUE',
  'eventDate': '2020-04-23',
  'eventDescriptionText': 'PG-Pub Issue Notification'},
 {'eventCode': 'RQPR',
  'eventDate': '2020-01-02',
  'eventDescriptionText': 'Request for Foreign Priority (Priority Papers May Be Included)'},
 {'eventCode': 'M844',
  'eventDate': '2020-01-03',
  'eventDescriptionText': 'Information Disclosure Statement (IDS) Filed'},
 {'eventCode': 'M844',
  'eventDate': '2020-01-02',
  'eventDescriptionText': 'Information Disclosure Statement (IDS) Filed'},
 {'eventCode': 'COMP',
  'eventDate': '2020-02-04',
  'eventDescriptionText': 'Application Is Now Complete'}]

然后，df['prosecutionHistoryDataBag.prosecutionHistoryData'][i][j] 会 return 字典：

{'eventCode': 'PG-ISSUE',
 'eventDate': '2020-04-23',
 'eventDescriptionText': 'PG-Pub Issue Notification'}

我想遍历 df['prosecutionHistoryDataBag.prosecutionHistoryData'] 中的每个条目以识别包含 'eventDescriptionText' 中特定字符串的行。

在上面的例子中df['prosecutionHistoryDataBag.prosecutionHistoryData']是一个系列，df['prosecutionHistoryDataBag.prosecutionHistoryData'][i]是一个列表，['prosecutionHistoryDataBag.prosecutionHistoryData'][i][j]是一个字典。

我想首先遍历列表 - 并针对每个列表遍历字典以查看 'eventDescriptionText' 是否包含特定字符串。

谢谢！

Answer 1

尝试使用以下代码。

for lst in df['prosecutionHistoryDataBag.prosecutionHistoryData']:
    for I in lst:
        if I.get("eventDescriptionText").find(your_string) != -1:
            # do something
            pass

Answer 2

如果我理解正确的话

df['prosecutionHistoryDataBag.prosecutionHistoryData']

实际上是一个列表，其元素是字典列表。另见上文。如果是这样，那么无聊的方式就是：

lst = df['prosecutionHistoryDataBag.prosecutionHistoryData']
for dicts in lst:
    for d in dicts:
        if d['eventDescriptionText'] == 'SOME TEXT YOU SEARCH FOR':
            code = d['eventCode']
            date = d['eventDate']
            # Do something with code and date.

现在，您可以 flatten that list of lists and use a generator:

lst = df['prosecutionHistoryDataBag.prosecutionHistoryData']
for d in (d for dicts in lst for d in dicts):
    if d['eventDescriptionText'] == 'SOME TEXT YOU SEARCH FOR':
        code = d['eventCode']
        date = d['eventDate']
        # Do something with code and date.

接下来，将测试也压缩到 lists-flattening-generator 中，以降低代码的可读性：

lst = df['prosecutionHistoryDataBag.prosecutionHistoryData']
for code, date in ((d['eventCode'], d['eventDate']) for dicts in lst for d in dicts if d['eventDescriptionText'] == 'SOME TEXT YOU SEARCH FOR'):
    # Do something with code and date.

filter() 函数对这里的可读性帮助不大

for code, date in ((d['eventCode'], d['eventDate']) for d in filter(lambda d: d['eventDescriptionText'] == 'SOME TEXT YOU SEARCH FOR', (d for dicts in lst for d in dicts))):
    # Do something with code and date.

但其他 itertools or more-itertools may be of use (e.g. the flatten() 函数）。

如何遍历包含字典的列表？

How to traverse lists containing a dictionary?

python

json

dictionary

list

data-analysis