Python error - List index out of range error but its not

Question

EDIT: Got it working now, Thanks. It was an empty line on the Text file as someone commented

Beginner here - I'm getting an error saying list index out of range, but I'm referencing a position in the list that should be in range. The error is on the line "courseGPA = GPAconverter(line[2])" which calls my function, GPAconverter.

Im trying to create a program that reads each line of a text file containing a course, the weight of that course, and the grade of that course. I want it to read the course grade, put it through a function i've created, and convert it to a GPA. Then eventually I want the code to output my final GPA.

The format of the txt file is:

Math, 0.5, 80

for line in inputFile:

    line = line.rstrip()
    line = line.split(",")
    courseGPA = GPAconverter(line[2])
    if float(line[1]) == 0.5:
        count = count + 1
        totalGPA += courseGPA
    elif float(line[1]) == 1.0:
        count = count + 2
        totalGPA += 2*(courseGPA)
    elif float(line[1]) == 2.0:
        count += 4
        totalGPA += 4*(courseGPA)
    else:
        print("Somethings wrong")

You are reading an empty line, ignore it by wrapping your code around an if condition `if line.strip():` — Devesh Kumar Singh, May 25 '19 at 15:49
list index starts from `0`. I think you are need `1` instead of `2`? — shaik moeed, May 25 '19 at 15:50
Also, just put triple ``` on the lines above and below your code to format it — marsnebulasoup, May 25 '19 at 15:53
Check `line`. If it says that it's our of bounds it is, so the data must be not what your expect. — Carcigenicate, May 25 '19 at 15:55
Devesh, not sure what you mean exactly, can you tell me what exactly id put where. and Do i need to take any lines out? — corey, May 25 '19 at 15:55
when I do print (line) the last two outputs are this (on separate lines btw), so maybe it has something to do with the very last line? : ['Geo', ' 0.5', ' 83'] [''] — corey, May 25 '19 at 15:57
Please [edit] your question to include the exact traceback and the precise input line on which this happens. — tripleee, May 25 '19 at 15:58
I mean to say before you do any operations in line, you need to check if it is an empty line, which you do by `if line.strip()`, since a empty line evaluates to False — Devesh Kumar Singh, May 25 '19 at 16:55

score 0 · Answer 1 · answered May 25 '19 at 15:57

0

It's highly possible that some records/line in textfile is having less than 3 tokens, it would be better to sanitize for the number of tokens before parsing or passing the tokens.

answered May 25 '19 at 15:57

nalamrc

11
2

marsnebulasoup · Answer 2 · 2019-07-31T21:52:34.123

I think this is what you're looking for:

def GPAconverter(param):
    #do something

with open("yourfile.txt") as file:
    inputFile = file.readlines()
    count = 0
    totalGPA = 0
    for line in inputFile:
        line = line.rstrip()
        line = line.split(",")
        courseGPA = GPAconverter(line[2])
        if float(line[1]) == 0.5:
            count = count + 1
            totalGPA += float(courseGPA)
        elif float(line[1]) == 1.0:
            count = count + 2
            totalGPA += 2*float(courseGPA)
        elif float(line[1]) == 2.0:
            count += 4
            totalGPA += 4*float(courseGPA)
        else:
            print("Something is wrong")

print(totalGPA)

Contents of yourfile.txt:

Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
Math, 0.5, 80
...
...

You should be able to replace the contents with whatever you need, but it must have at least three columns, and the second and third elements must be numbers, or it will throw an error, unless you edit the code to work differently.

As @Devesh Kumar Singh said, you might have empty lines in your file. This code should remove them:

import fileinput
for line in fileinput.FileInput("file",inplace=1):
    if line.rstrip():
        print(line)

source: How to delete all blank lines in the file with the help of python?, @ghostdog74

@corey You are welcome. Please consider [accepting my answer](https://meta.stackexchange.com/questions/5234/how-does-accepting-an-answer-work) if it works for you — marsnebulasoup, May 26 '19 at 19:56

Python error - List index out of range error but its not

2 Answers2