Extending a list with Python

Question

Trying to extend a list with python and really in struggle town. Basically I'm pulling XML data and then taking what I need into a list and then trying to save it in a file. I plan on taking the data every 30 minutes (creating road congestion data ! :D).

Really appreciate any help - this is all a big learning curve for me.

Cheers - Here is the data below. I've given a similar XML data as the data I have has a private key.

from lxml import etree
import urllib.request
import pickle

#append to list next
def handleLeg(leg):
   # print this leg as text, or save it to file maybe...
   text = etree.tostring(leg, pretty_print=True)
   # also process individual elements of interest here if we want
   tagsOfInterest=["noTrafficTravelTimeInSeconds", "lengthInMeters", "departureTime", "trafficDelayInSeconds"]  # whatever
   #list to use for data analysis
   global data
   data = []
   for child in leg:
       if 'summary' in child.tag:
          for elem in child:
              for item in tagsOfInterest:
                  if item in elem.tag:
                      print (item + " : " + elem.text)
"""
Traceback (most recent call last):


File "/home/Hewlbern/noobie/newfile.py", line 40, in <module>
    parseXML("xmlFile")
  File "/home/Hewlbern/noobie/newfile.py", line 32, in parseXML
    handleLeg(child)
  File "/home/Hewlbern/noobie/newfile.py", line 20, in handleLeg
    data.extend = (item + " : " + elem.text)

AttributeError: 'list' object attribute 'extend' is read-only

"""
                      data.extend = (item + " : " + elem.text)
def parseXML(xmlFile):
   """
   Parse the xml
   """
   with urllib.request.urlopen("https://api.tomtom.com/routing/1/calculateRoute/-37.79205923474775,145.03010268799338:-37.798883995180496,145.03040309540322:-37.807106781970354,145.02895470253526:-37.80320743019992,145.01021142594075:-37.7999012967757,144.99318476311566:?routeType=shortest&key=NOKEYBISHcomputeTravelTimeFor=all") as fobj:
       xml = fobj.read()
#Look at Parent and Child XML organisation as this is where the data is going wrong at the moment
   root = etree.fromstring(xml)

   for child in root:
       if 'route' in child.tag:
           handleLeg(child)
           """for elem in child:
               if 'leg' in elem.tag:
                   handleLeg(elem)
"""


if __name__ == "__main__":
   parseXML("xmlFile")

pickling_on = open("data.pickle","wb")
pickle.dump(data, pickling_on)
pickling_on.close()

pickle_off = open("data.pickle","rb")
data = pickle.load(pickle_off)
print(data)



<summary>
<lengthInMeters>5144</lengthInMeters>
<travelTimeInSeconds>764</travelTimeInSeconds>
<trafficDelayInSeconds>0</trafficDelayInSeconds>
<departureTime>2017-12-28T14:42:14+11:00</departureTime>
<arrivalTime>2017-12-28T14:54:58+11:00</arrivalTime>
<noTrafficTravelTimeInSeconds>478</noTrafficTravelTimeInSeconds>
<historicTrafficTravelTimeInSeconds>764</historicTrafficTravelTimeInSeconds>
<liveTrafficIncidentsTravelTimeInSeconds>764</liveTrafficIncidentsTravelTimeInSeconds>
</summary>
<leg>
<summary>
<lengthInMeters>806</lengthInMeters>
<travelTimeInSeconds>67</travelTimeInSeconds>
<trafficDelayInSeconds>0</trafficDelayInSeconds>
<departureTime>2017-12-28T14:42:14+11:00</departureTime>
<arrivalTime>2017-12-28T14:43:21+11:00</arrivalTime>
<noTrafficTravelTimeInSeconds>59</noTrafficTravelTimeInSeconds>
<historicTrafficTravelTimeInSeconds>67</historicTrafficTravelTimeInSeconds>
<liveTrafficIncidentsTravelTimeInSeconds>67</liveTrafficIncidentsTravelTimeInSeconds>
</summary>

One of the examples given is great but is giving me this output ( from data.extend(item + " : " + elem.text) )

['l', 'e', 'n', 'g', 't', 'h', 'I', 'n', 'M', 'e', 't', 'e', 'r', 's', ' ', ':', ' ', '5', '1', '4', '5', 't', 'r', 'a', 'f', 'f', 'i', 'c', 'D', 'e', 'l', 'a', 'y', 'I', 'n', 'S', 'e', 'c', 'o', 'n', 'd', 's
', ' ', ':', ' ', '2', '8', '2', 'd', 'e', 'p', 'a', 'r', 't', 'u', 'r', 'e', 'T', 'i', 'm', 'e', ' ', ':', ' ', '2', '0', '1', '8', '-', '0', '1', '-', '2', '4', 'T', '1', '7', ':', '1', '2', ':', '5', '2', 
'+', '1', '1', ':', '0', '0', 'n', 'o', 'T', 'r', 'a', 'f', 'f', 'i', 'c', 'T', 'r', 'a', 'v', 'e', 'l', 'T', 'i', 'm', 'e', 'I', 'n', 'S', 'e', 'c', 'o', 'n', 'd', 's', ' ', ':', ' ', '4', '8', '9']
>>> 

Answer 1

Depending on what you want, try:

data.extend(item + " : " + elem.text)

or

data.append(item + " : " + elem.text)