Python - IndexError: list index out of range - but only in one column of data

Question

I'm trying to read through a CSV file that has a couple thousand rows and 3 columns of data. I'm successfully reading through the first and second column, but when I attempt to read through the third column I get an out of range error. In other words:

row=0
rowMax = len(AudioAngle)
while row < rowMax:
    print (AudioAngle[row][0])
    print (AudioAngle[row][1])
    row=row+1

both work and when I add in

print (AudioAngle[row][2])

things only work until the 274th row.
Looking at my CSV file I see this at that line.

00:09.0    0    0
00:09.0    0    0
00:09.0    0    0
00:09.1             <--- line 274
00:09.1    0    0
00:09.1    0    0
00:09.2    0    0

The code has no issue with the empty space in the second column but throws the error in the third column.

Why is this third column throwing an index out of range error at me when I try to read through it?

I'm seeing four columns in your CSV file, and it appears that the third one is the first column with a blank - that seems consistent with your `IndexError`. Is the first column in AudioAngle not the row numbers? — Brionius, Aug 21 '13 at 17:13
sorry for the confusion, the first column you saw was actually row numbers added in by myself - edited that to make it clearer — stoves, Aug 21 '13 at 17:16
tried to make things clearer Brent - I'm getting an out of range error and I don't know why. my code runs perfectly fine for the first two columns and the second column has identical empty space compared to the third column — stoves, Aug 21 '13 at 17:29

score 2 · Accepted Answer · answered Aug 21 '13 at 17:32

The parser might just use the space as a separator - thus the space between both first and second, and the second and third column could be seen as separating the first cell from a empty cell in the second column. To get rid of the error, just check for the sublist length! (And please use a for loop...)

for row in AudioAngle:
    print(row[0])
    print(row[1])
    if len(row) >= 3:
       print(row[2])

score 0 · Answer 2 · answered Aug 21 '13 at 17:35

It makes sense that you will get an index out of range on the 274 row because [1] and [2] don't exist.

If you data may or may not be present, as in the case on line 274, you will need to check to see if it exists before you attempt to use it:

if (AudioAngle[row][0]):
    print (AudioAngle[row][0])

Python - IndexError: list index out of range - but only in one column of data

2 Answers2