Converts JSON of a specific format to CSV

README.md

####Converts JSON of the format

[
  {
    "target": "target1", 
    "datapoints": [
      [val1,timestamp1],
       ...
      [valN,timestampN]]
  } , {
    ...
  } , {
    "target": "targetN",
    "datapoints": [datapointsN]
  }
]

####to CSV of the format

timestamp, target1, ..., targetN
timestamp1, val1, ..., valN
...
timestampN, ...

json_to_csv.py

import csv
import json

x="""[{"target": "riak-1_local.cpu-user", "datapoints": [[0.40005200000000002, 1383329710], [0.39994499999999999, 1383329720], [0.50004199999999999, 1383329730], [0.399978, 1383329740], [null, 1383329750], [0.29998599999999997, 1383329760], [24.100829000000001, 1383329770], [32.001468000000003, 1383329780], [33.498116000000003, 1383329790], [34.302287, 1383329800], [35.495013, 1383329810], [36.502111999999997, 1383329820], [35.200415, 1383329830], [37.100186999999998, 1383329840], [35.601599999999998, 1383329850], [36.600332000000002, 1383329860], [36.171678, 1383329870], [null, 1383329880], [36.314202999999999, 1383329890], [36.695945999999999, 1383329900], [null, 1383329910], [35.401983000000001, 1383329920], [36.899768000000002, 1383329930], [36.300564000000001, 1383329940], [35.099674, 1383329950], [36.199824, 1383329960], [36.399842999999997, 1383329970], [34.199278999999997, 1383329980], [36.901499999999999, 1383329990], [35.397424999999998, 1383330000], [35.202129999999997, 1383330010], [37.138508999999999, 1383330020], [null, 1383330030], [36.129519999999999, 1383330040], [36.701092000000003, 1383330050], [36.200173999999997, 1383330060], [35.395482999999999, 1383330070], [36.804374000000003, 1383330080], [36.100309000000003, 1383330090], [34.799944000000004, 1383330100], [36.700296000000002, 1383330110], [35.899487000000001, 1383330120], [36.495987999999997, 1383330130], [null, 1383330140], [36.600890999999997, 1383330150], [35.401741999999999, 1383330160], [36.496845, 1383330170], [35.303964000000001, 1383330180], [34.599359, 1383330190], [36.699393999999998, 1383330200], [35.599291000000001, 1383330210], [34.297795000000001, 1383330220], [36.503644000000001, 1383330230], [36.899951000000001, 1383330240], [35.500464000000001, 1383330250], [37.099918000000002, 1383330260], [34.799821999999999, 1383330270], [34.600138000000001, 1383330280], [36.598146999999997, 1383330290], [36.101740999999997, 1383330300], [36.700054999999999, 1383330310], [38.297044, 1383330320], [36.001655999999997, 1383330330], [null, 1383330340], [37.800476000000003, 1383330350], [35.900351999999998, 1383330360], [34.799481, 1383330370], [36.700104000000003, 1383330380], [35.597507999999998, 1383330390], [35.801769, 1383330400], [36.598833999999997, 1383330410], [35.902337000000003, 1383330420], [35.994529999999997, 1383330430], [36.605032999999999, 1383330440], [35.699433999999997, 1383330450], [35.501041999999998, 1383330460], [36.399276999999998, 1383330470], [37.000759000000002, 1383330480], [36.599989000000001, 1383330490], [35.699967000000001, 1383330500], [36.100065000000001, 1383330510], [36.899856999999997, 1383330520], [36.297961000000001, 1383330530], [35.499901000000001, 1383330540], [34.800795000000001, 1383330550], [35.701174999999999, 1383330560], [36.695765999999999, 1383330570], [null, 1383330580], [36.002025000000003, 1383330590], [35.497917999999999, 1383330600], [36.802222999999998, 1383330610], [36.100008000000003, 1383330620], [null, 1383330630], [35.747754, 1383330640], [34.404614000000002, 1383330650], [35.795636000000002, 1383330660]]}, 
      {"target": "riak-2_local.cpu-user", "datapoints": [[null, 1383329710], [null, 1383329720], [null, 1383329730], [null, 1383329740], [null, 1383329750], [null, 1383329760], [20.499922999999999, 1383329770], [31.989488999999999, 1383329780], [null, 1383329790], [34.205795000000002, 1383329800], [34.499645000000001, 1383329810], [35.400033000000001, 1383329820], [35.799894000000002, 1383329830], [37.399762000000003, 1383329840], [35.597549000000001, 1383329850], [36.084896999999998, 1383329860], [null, 1383329870], [36.309189000000003, 1383329880], [35.398574000000004, 1383329890], [37.000981000000003, 1383329900], [36.100473999999998, 1383329910], [36.099677999999997, 1383329920], [37.100155999999998, 1383329930], [35.793717000000001, 1383329940], [null, 1383329950], [37.102761000000001, 1383329960], [36.200445999999999, 1383329970], [34.700367, 1383329980], [36.397944000000003, 1383329990], [null, 1383330000], [35.599984999999997, 1383330010], [36.598111000000003, 1383330020], [34.900575000000003, 1383330030], [null, 1383330040], [35.151364999999998, 1383330050], [35.500622, 1383330060], [35.900013999999999, 1383330070], [36.700114999999997, 1383330080], [35.599651000000001, 1383330090], [35.200006000000002, 1383330100], [35.800119000000002, 1383330110], [37.098466000000002, 1383330120], [36.200750999999997, 1383330130], [36.90081, 1383330140], [34.798155000000001, 1383330150], [35.101610999999998, 1383330160], [35.299781000000003, 1383330170], [34.796194999999997, 1383330180], [null, 1383330190], [36.902293, 1383330200], [35.399869000000002, 1383330210], [34.897413999999998, 1383330220], [36.599879000000001, 1383330230], [34.900506, 1383330240], [35.599452999999997, 1383330250], [36.002763000000002, 1383330260], [34.900360999999997, 1383330270], [35.099972999999999, 1383330280], [36.899659, 1383330290], [35.500442999999997, 1383330300], [36.697311999999997, 1383330310], [37.902737000000002, 1383330320], [35.899991999999997, 1383330330], [36.999088, 1383330340], [36.100845, 1383330350], [35.099674999999998, 1383330360], [34.599791000000003, 1383330370], [37.099742999999997, 1383330380], [35.999665999999998, 1383330390], [34.100796000000003, 1383330400], [36.294835999999997, 1383330410], [35.999450000000003, 1383330420], [null, 1383330430], [36.302320999999999, 1383330440], [35.301265999999998, 1383330450], [35.099715000000003, 1383330460], [36.298678000000002, 1383330470], [36.401409999999998, 1383330480], [35.898851000000001, 1383330490], [37.301402000000003, 1383330500], [37.099114, 1383330510], [35.097926000000001, 1383330520], [36.602200000000003, 1383330530], [36.200707000000001, 1383330540], [34.999499999999998, 1383330550], [36.300724000000002, 1383330560], [36.600048000000001, 1383330570], [35.499988999999999, 1383330580], [36.597861999999999, 1383330590], [35.986051000000003, 1383330600], [null, 1383330610], [35.807819000000002, 1383330620], [34.899963, 1383330630], [36.099128999999998, 1383330640], [35.900955000000003, 1383330650], [35.196418999999999, 1383330660]]}, 
      {"target": "riak-3_local.cpu-user", "datapoints": [[null, 1383329710], [null, 1383329720], [null, 1383329730], [null, 1383329740], [null, 1383329750], [null, 1383329760], [null, 1383329770], [null, 1383329780], [null, 1383329790], [null, 1383329800], [null, 1383329810], [null, 1383329820], [null, 1383329830], [null, 1383329840], [null, 1383329850], [null, 1383329860], [null, 1383329870], [null, 1383329880], [null, 1383329890], [null, 1383329900], [null, 1383329910], [12.899831000000001, 1383329920], [13.999874999999999, 1383329930], [12.500126, 1383329940], [13.099738, 1383329950], [13.400293, 1383329960], [12.698869, 1383329970], [12.400017, 1383329980], [14.801413999999999, 1383329990], [13.999974999999999, 1383330000], [13.399849, 1383330010], [14.500127000000001, 1383330020], [13.100089000000001, 1383330030], [12.298672, 1383330040], [13.701591000000001, 1383330050], [12.999002000000001, 1383330060], [null, 1383330070], [13.100443, 1383330080], [12.999758999999999, 1383330090], [12.500068000000001, 1383330100], [13.898173, 1383330110], [12.801826999999999, 1383330120], [14.000128, 1383330130], [12.199833, 1383330140], [12.799003000000001, 1383330150], [12.801233, 1383330160], [13.198169999999999, 1383330170], [12.400819, 1383330180], [13.400679, 1383330190], [13.899986999999999, 1383330200], [13.099266, 1383330210], [13.000147999999999, 1383330220], [13.80054, 1383330230], [13.000019, 1383330240], [13.199187, 1383330250], [null, 1383330260], [13.100438, 1383330270], [13.800132, 1383330280], [13.199611000000001, 1383330290], [13.699113000000001, 1383330300], [13.101076000000001, 1383330310], [13.800143, 1383330320], [13.596754000000001, 1383330330], [13.70046, 1383330340], [13.802882, 1383330350], [14.798598, 1383330360], [13.801253000000001, 1383330370], [13.699858000000001, 1383330380], [12.800185000000001, 1383330390], [12.599209999999999, 1383330400], [null, 1383330410], [13.500416, 1383330420], [13.099943, 1383330430], [11.699643999999999, 1383330440], [13.300288999999999, 1383330450], [13.399867, 1383330460], [13.300268000000001, 1383330470], [13.999653, 1383330480], [13.400366999999999, 1383330490], [12.699908000000001, 1383330500], [12.600102, 1383330510], [null, 1383330520], [12.200013, 1383330530], [13.199911, 1383330540], [13.098337000000001, 1383330550], [12.501424, 1383330560], [12.900067999999999, 1383330570], [13.800126000000001, 1383330580], [13.199908000000001, 1383330590], [12.800095000000001, 1383330600], [13.099945999999999, 1383330610], [12.199956999999999, 1383330620], [13.599061000000001, 1383330630], [13.100757, 1383330640], [12.999215, 1383330650], [12.699999999999999, 1383330660]]}]"""

x = json.loads(x)
f = csv.writer(open("output.csv", "wb+"))

header = ["timestamp"]

# Build dict of {timestamp: [target_value1, target_value2, target_value3],...}
rows = {}
for i in x:
    header.append(i['target'])
    for j in i['datapoints']:
        if not rows.has_key(j[1]):
            rows[j[1]] = []
        rows[j[1]].append(j[0])

# Write header
f.writerow(header)

# Write rows
for i in rows:
    f.writerow([i] + rows[i])