Iterating Generators in a For Loop in Python

Question

I'm trying to parse XML from the National Weather Service ; printing the hourly temperature, a blank space, and the associated time of that hourly temperature.

Printing the temperatures simply requires a for loop. The problem is indexing the correct time-stamp while looping and printing each temperature. Example children in /data/time-layout look like this:

<layout-key>k-p1h-n1-0</layout-key>
<start-valid-time>2014-06-30T13:00:00-05:00</start-valid-time>
<end-valid-time>2014-06-30T14:00:00-05:00</end-valid-time>
<start-valid-time>2014-06-30T14:00:00-05:00</start-valid-time>
<end-valid-time>2014-06-30T15:00:00-05:00</end-valid-time>

The desired snippets are all and only "start-valid-time" nodes.

Here is the code I have so far:

import elementtree.ElementTree as ET
import urllib2  

url = "http://forecast.weather.gov/MapClick.php?lat=36.06000&lon=-94.16000&FcstType=digitalDWML"
tree = ET.parse(urllib2.urlopen(url))
forecast = tree.getroot()
i = int(0)

Temperatures = forecast.find("./data/parameters/temperature[@type='hourly']")

for HourTemperature in Temperatures:
    TimeStamps = forecast.findall("./data/time-layout/start-valid-time") #Reference 1
    print HourTemperature.text, "  ", TimeStamps[i].text #Reference 2
    i += 1

Running "python [program name].py" yields

TypeError: 'generator' object has no attribute '__getitem__'

Which makes sense when the above lines Reference 1 and 2 are wrong. I believe my problem is caused by a misunderstanding of generators.

Thank ya'll in advance.

Answer 1

Your code works fine here with a slight import modification that may have to do with me running python 2.7.4 on Ubuntu.

import xml.etree.ElementTree as ET

The rest works as is.