How to fix "list index out of range" error?

[Karen Rosen]

This is my first program of any sort I am getting this error

File "karenrosen5.py ", line 162, in <module>
record.append(t riad("NoReleve" ,line))
File "karenrosen5.py ", line 115, in triad
item = data[fields2[key]]
IndexError: list index out of range

The code in question is

def triad(key,data):
    try:
        assert key in fields
    except:
        print "key %s not found" %key
        raise ValueError,key
    item = data[fields2[key]]
    if key in noblanks:
        item = item.replace(" ","")
    if key.startswith("_"):
        key = key.replace("_","")    # hack for double column names
    if isblank(item):
        if defaults:
            if key in defaults.keys():
                return  "<%s>"%key+defaults[key]+"</%s>"%key
            else:
                return  "<%s>"%key+"(inconnu)</%s>"%key
        else:
            print line
            raise BadLine
    return "<%s>"%key+item+"</%s>"%key

defaults = {"NAS":"000000000","A_DateNaissance":"1/1/20","B1_NbJoursGarde":"0"}
noblanks = ["NAS","CodePostal"]


filename = "KR.tsv"
outname = "KR5.xml"

outfile = file(outname,"w")

data = [item.strip().split("\t") for item in file(filename).readlines()]
fields = data[0]
fields2 = dict([(item[1],item[0]) for item in enumerate(fields)])

# hack for double column names
fields2["_Prenom"]=4
fields2["_NomFamille"]=3

fields += "_Prenom _NomFamille".split()
# end hack for double column names

print fields2

outfile.write(prefix)
            
for line in data[1:]:
    if not [item for item in line if (not isblank(item))]:
        break     # TSV file ends with many blank lines; exit and clean up on first one
    try:
        record = ["\n\n<R>"]

        record.append(triad("Annee",line))
        record.append(triad("NoReleve",line))

        record.append("<Payeur>")

        record.append(triad("NAS",line))
        record.append(triad("_NomFamille",line))
        record.append(triad("_Prenom",line))

        record.append("<Adresse>")
        record.append(triad("Ligne1",line))
        record.append(triad("Ville",line))
        record.append(triad("Province",line))        
        record.append(triad("CodePostal",line))
        record.append("</Adresse>")

        record.append("</Payeur>")

        record.append("<Enfant>")

        record.append(triad("NomFamille",line))
        record.append(triad("Prenom",line))
        record.append(triad("A_DateNaissance",line))

        record.append("<CaseB>")
        record.append(triad("B1_NbJoursGarde",line))
        record.append("</CaseB>")

        record.append("<Montants>")
        record.append(triad("C_FraisPayes",line))
        record.append("</Montants>")
        
        record.append("</Enfant>")

        record.append("</R>") 
        record = "\n".join(record)
        outfile.write(record)
    except BadLine:
        pass

[bvdet]

To debug this, make a series of print statements prior to the line with the error.

print data
print fields2
print key

The error message is telling you that the list index is not valid for the list. Example:

>>> s = [0,1,2,3,4,5]
>>> s[6]
Traceback (most recent call last):
  File "<interactive input>", line 1, in ?
IndexError: list index out of range
>>>