python - JSON 提取到 pandas 数据帧

Question

我目前正在尝试将 json 作为 pandas 数据帧进行处理。这里发生的事情是我得到了连续的 json 结构流。它们只是附加的。这是一整行。我从中提取了一个 .txt 并想现在通过 pandas 对其进行分析。

示例片段:

{"positionFlightMessage":{"messageUuid":"95b3b6ca-5dd2-44b4-918a-baa51022d143","schemaVersion":"1.0-RC1","timestamp":1533134514,"flightNumber":"DLH1601","position":{"waypoint":{"latitude":44.14525,"longitude":-1.31849},"flightLevel":340,"heading":24.0},"messageSource":"ADSB","flightUniqueId":"AFR1601-1532928365-airline-0002","airlineIcaoCode":"AFR","atcCallsign":"AFR89GA","fuel":{},"speed":{"groundSpeed":442.0},"altitude":{"altitude":34000.0},"nextPosition":{"waypoint":{}},"messageSubtype":"ADSB"}}{"positionFlightMessage":{"messageUuid":"884708c1-2fff-4ebf-b72c-bbc6ed2c3623","schemaVersion":"1.0-RC1","timestamp":1533134515,"flightNumber":"DLH012","position":{"waypoint":{"latitude":37.34542,"longitude":143.79951},"flightLevel":320,"heading":54.0},"messageSource":"ADSB","flightUniqueId":"EVA12-1532928367-airline-0096","airlineIcaoCode":"DLH","atcCallsign":"EVA012","fuel":{},"speed":{"groundSpeed":462.0},"altitude":{"altitude":32000.0},"nextPosition":{"waypoint":{}},"messageSubtype":"ADSB"}}...

正如您所看到的，每个 json 都以 {"positionFlightMessage": 开头，并以 messageSubtype":"ADSB" 结尾

一个 json 结束后，下一个 json 会追加到它后面。

我需要的是一个表格，如下所示:

95b3b6ca-5dd2-44b4-918a-baa51022d143    1.0-RC1 1533134514  DLH1601 4.414.525   -131.849    340 24.0    ADSB    AFR1601-1532928365-airline-0002 AFR AFR89GA 442.0   34000.0 ADSB
884708c1-2fff-4ebf-b72c-bbc6ed2c3623    1.0-RC1 1533134515  DLH012  3.734.542   14.379.951  320 54.0    ADSB    EVA12-1532928367-airline-0096   DLH EVA012  462.0   32000.0 ADSB

我尝试使用 pandas 读取 json 但出现错误。

import pandas as pd

df = pd.read_json("tD.txt",orient='columns')

df.head()

ValueError: Trailing data

tD.txt 具有上面给定的片段，没有最后一个 (...) 点

我认为问题是，每个 json 都是附加的。我可以在每个之后添加一个新行

messageSubtype":"ADSB"}}

然后阅读它，但也许你有一个解决方案，我可以直接转换大txt文件并将其轻松转换为df

Answer 1

尝试让 json 流输出如下:

注意开头“[”和结尾“]”。另请注意每个 json 输入之间的“,”。

data = [{
    "positionFlightMessage": {
        "messageUuid": "95b3b6ca-5dd2-44b4-918a-baa51022d143",
        "schemaVersion": "1.0-RC1",
        "timestamp": 1533134514,
        "flightNumber": "DLH1601",
        "position": {
            "waypoint": {
                "latitude": 44.14525,
                "longitude": -1.31849
            },
            "flightLevel": 340,
            "heading": 24.0
        },
        "messageSource": "ADSB",
        "flightUniqueId": "AFR1601-1532928365-airline-0002",
        "airlineIcaoCode": "AFR",
        "atcCallsign": "AFR89GA",
        "fuel": {},
        "speed": {
            "groundSpeed": 442.0
        },
        "altitude": {
            "altitude": 34000.0
        },
        "nextPosition": {
            "waypoint": {}
        },
        "messageSubtype": "ADSB"
    }
}, {
    "positionFlightMessage": {
        "messageUuid": "884708c1-2fff-4ebf-b72c-bbc6ed2c3623",
        "schemaVersion": "1.0-RC1",
        "timestamp": 1533134515,
        "flightNumber": "DLH012",
        "position": {
            "waypoint": {
                "latitude": 37.34542,
                "longitude": 143.79951
            },
            "flightLevel": 320,
            "heading": 54.0
        },
        "messageSource": "ADSB",
        "flightUniqueId": "EVA12-1532928367-airline-0096",
        "airlineIcaoCode": "DLH",
        "atcCallsign": "EVA012",
        "fuel": {},
        "speed": {
            "groundSpeed": 462.0
        },
        "altitude": {
            "altitude": 32000.0
        },
        "nextPosition": {
            "waypoint": {}
        },
        "messageSubtype": "ADSB"
    }
}]

现在您应该能够循环 json 中的每个“列表”元素并将其附加到 pandas df。

print(len(data))
for i in range(0,len(data)):
    #here is just show messageSource only. Up to you to find out the rest..
    print(data[i]['positionFlightMessage']['messageSource'])
    #instead of printing here you should append it to pandas df.

希望这对您有所帮助。