IndexError: list index out of range when trying to add a list of values to DataFrame columns

Question

I have a dataframe column NVD where each row contains a list. What I did was create a few new columns and I'd like to add the first value from the list to a specific column, the second value from the list to another etc. However I'm running into this error IndexError: list index out of range

Here's my starting DataFrame:

poam = pd.read_excel('NetApp-RET-NVD_V1.xlsx', header = 0)
new_poam = poam[["POAM ID ", 'NVD']]

# Split string into separate values and create list from values
new_poam['NVD'] = new_poam['NVD'].astype(str)
new_poam['NVD'] = [x[10:] for x in new_poam['NVD']]
new_poam['NVD'] = [x.replace("\/", ",") for x in new_poam['NVD']]
new_poam['NVD'] = [x.split(",") for x in new_poam['NVD']]
print(new_poam)

>>> Output

    POAM ID                                            NVD
0     V-1744  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]
1     V-1747  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]
2     V-1748  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]
3     V-1749  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]
4     V-1751  [AV:N, AC:L, PR:L, UI:N, S:U, C:N, I:N, A:H]
..       ...                                           ...
200   V-2080                                            []
201   V-2082                                            []
202   V-2083                                            []
203   V-2084                                            []
204   V-2085                                            []

Column NVD is a list of values like I wanted- so now I wanted to add all of my new columns and add values from the lists to those columns, here's how I accomplished that:

new_poam.reindex(columns = new_poam.columns.tolist() + ['Attack Vector','Attack Complexity', 'Privileges Required', 'User Interaction', 'Impact Metrics: Confidentiality', 'Impact Metrics: Integrity', 'Impact Metrics: Availability', 'Remediation Level', 'List of Risk Reeduction'])
new_poam['Attack Vector'] = [x[0] for x in new_poam['NVD']]
print(new_poam)

>>> Output

    POAM ID                                            NVD Attack Vector
0     V-1744  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]          AV:N
1     V-1747  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]          AV:N
2     V-1748  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]          AV:N
3     V-1749  [AV:N, AC:L, PR:H, UI:N, S:U, C:N, I:N, A:H]          AV:N
4     V-1751  [AV:N, AC:L, PR:L, UI:N, S:U, C:N, I:N, A:H]          AV:N
..       ...                                           ...           ...
200   V-2080                                            []              
201   V-2082                                            []              
202   V-2083                                            []              
203   V-2084                                            []              
204   V-2085                                            []              

So you can see that the first value from my lists got added to the Attack Vector column, but now when I try adding the second value from the lists to the Attack Complexity column like so:

new_poam['Attack Complexity'] = [x[1] for x in new_poam['NVD']]

I get the error mentioned earlier IndexError: list index out of range I'm assuming this happens because some of the rows for the NVD column have no values, so it's an empty list. When I add the [0] value from the list, it just does nothing with the empty lists, but then when I add any other values, I think that's what's causing the error? If that's the case, how do I make it just add a generic "Null" value to each of the new columns, if it's an empty list?

Answer 1

In this case, just make an if statement

l = []
for i in new_poam['NVD']:
    if not i:
       l.append('0')
    else:
       try:
           l.append(i[1])
       except:
           l.append('0')
df['new_column'] = l

The condition if not will check if your list is empty