Reputation: 55
I'm currently trying to process a json as pandas dataframe. What happened here is that I get a continuous stream of json structures. They are simply appended. It's a whole line. I extracted a .txt from it and want to analyse it now via pandas.
Example snippet:
{"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"}}...
as you see in this light snipped is, that every json starts with {"positionFlightMessage":
and ends with messageSubtype":"ADSB"
After a json ends, the next json just appends after it.
What i need is a table out of it, like this:
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
i tried to use pandas read json but i get a error.
import pandas as pd
df = pd.read_json("tD.txt",orient='columns')
df.head()
ValueError: Trailing data
tD.txt has the above given snippet without the last (...) dots
I think the problem is, that every json is just appended. I could add a new line after every
messageSubtype":"ADSB"}}
and then read it, but maybe you have a solution where i can just convert the big txt file directly and convert it easily to a df
Upvotes: 1
Views: 164
Reputation: 1377
Now here's a solution for your JSON as is using regex.
s = '{"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"}}'
import re
import json
replaced = json.loads('['+re.sub(r'{\"positionFlightMessage*', ',{\"positionFlightMessage', s)[1:] + ']')
dfTemp = pd.DataFrame(data=replaced)
df = pd.DataFrame()
counter = 0
def newDf(row):
global df,counter
counter += 1
temp = pd.DataFrame([row])
df = df.append(temp)
dfTemp['positionFlightMessage'] = dfTemp['positionFlightMessage'].apply(newDf)
print(df)
{"positionFlightMessage
with ,{"positionFlightMessage
and discard the first separator.Upvotes: 0
Reputation: 561
Try to get the stream of json to output like the following:
Notice the starting '[' and the ending ']'. Also notice the ',' between each json input.
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"
}
}]
Now you should be able to loop over each 'list' element in the json and append it to the 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.
Hope this helps you out a bit.
Upvotes: 1