遍历CSV文件时“列表索引超出范围”

Question

A strange thing is happening over here, I'm trying to add two extra line to an existing csv file, so I open it (edit1.csv), re-write it to a new file (edit2) with two extra line (one with the number 100 written on the first space, and a second row with the number 9 in the first three space.

ifile  = open('C:\PyProject\edit1.csv', "rb")
reader = csv.reader(ifile)
edited  = open('C:\PyProject\edit2.csv', "wb")
writer = csv.writer(edited, delimiter=',')
for row in reader:
    writer.writerow(row)
writer.writerow([100])
writer.writerow('999')
edited.close()
ifile.close()

So far so good, I get a new file (edit2.csv) that looks exactly like I want it to look.

The problem is when I'm trying to iterate through the new file in order to find the rows in which the second column is empty (see below), I get an error

-

with open('C:\PyProject\edit2.csv') as csvfile:
    readCSV = csv.reader(csvfile, delimiter=',')
    sec_col = []
    for row in readCSV:
        blanker = row[1]
        sec_col.append(blanker)
    trial_index = [i for i,x in enumerate(sec_col) if x == '']   

-

  blanker = row[1]
    IndexError: list index out of range

The strange thing is that if i open the new file and delete all the blank rows after the two I have manually added, the code runs just fine.

Sorry if my code is a bit messy, I'm still new at this :)

Thanks.

Answer 1

The only wrong part is accessing row[1] directly.

If row has only 1 row, then it throws exception when you are trying to reach the second.

Just modify the code like this:

for row in readCSV:
    if len(row) < 2: # row[1] not exists
        sec_col.append(row)