List Index out of range in Recurrent Nural Network

[Saad Bin Ahmed]

I have not too much experience in python. Here goes my problem. I am writing the code for recurrent neural network in order to recognize words given as .xml file and search in the dictionary which word .xml file conatins.
For this task I have initially defined labels of characters, then read the lines in .xml file and then try to figure out which word it contains, but here it shows List Index out of range error.

labels contain the characters

from optparse import OptionParser
import sys
import os
from xml.dom.minidom import parse
 
labels = ['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g','ga', 'h', 'i', 'j', 'k', 'km', 'l', 'm', 'n', 'o', 'p', 'pt','q','r','s','sc','sp','t','u','v','w','x','y','z']

I have some words defined in dictionary and some .xml files which I have to train by using dictionary words. But the problem I am suffering now is how can I search a word (by taking .xml file and explore it which word it contains, and search against it in a dictionary).

inputFilename = args [0]
ncFilename = args[1]
print options
print "input filename", inputFilename
print "data filename", ncFilename
seqDims = []
seqLengths = []
targetStrings = []
wordTargetStrings = []
seqTags = []
inputs = []
print "reading data files"
for l in file(inputFilename).readlines():
    xmlfile = l.strip()
    if len(xmlfile):
        print xmlfile
        seqTags.append(xmlfile)
        if os.path.exists(xmlfile):
            word = parse(xmlfile).getElementsByTagName('hwData')[0].getElementsByTagName('label')[0].getElementsByTagName('alternate')[0].getAttribute('value').strip().replace(' ','*')
            print 'WORD',word
            wts = word.encode('unicode_escape')
            print "WTS",wts
            wordTargetStrings.append(wts)    
            ts = ""
            for c in word:
                label = c.encode('unicode_escape')
                ts += label + ' '
            ts = ts.strip()
            print ts
            targetStrings.append(ts)
        else:
            wordTargetStrings.append(' ')
            targetStrings.append(' ')            
        oldlen = len(inputs)
        for trace in parse(xmlfile).getElementsByTagName('trace'):        
            for coords in trace.firstChild.nodeValue.split(','):
                pt = coords.split()
                inputs.append([float(pt[0]), float(pt[1]), 0.0])
            inputs[-1][-1] = 1
        seqLengths.append(len(inputs) - oldlen)
        seqDims.append([seqLengths[-1]])

When I execute this code it shows me the following error

word = parse(xmlfile).getElementsByTagName('hwData')[0].getElementsByTagName('label')[0].getElementsByTagName('alternate')[0].getAttribute('value').strip().replace(' ','*')
IndexError: list index out of range

Any Suggestions.....

[bvdet]

The problem is one of the calls to getElementsByTagName is returning an empty list, as in:

>>> s = []
>>> s[0]
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
IndexError: list index out of range
>>>