[FIXED] How does the following code result in the last column of the dataset being removed?

Issue

I am going through dataquest courses with this particular one using python/jupyter notebook Here is the main part of the code I am struggling with:

index = 0
for row in data:
    data[index] = row[:-1]
    index += 1

panda and re were imported via a helper.py

I am mainly unsure of the purpose of making data[index] = row[-1] but any help would be appreciated

Solution

It is not easy to answer this question without knowing the structure of data. I assume that data is a nested list. The code then causes the last element in each sublist of data to be removed.

Example:

data = [[1,2],[3,4],[5,6],[7,8]]

index = 0
for row in data:
    data[index] = row[:-1]
    index += 1
    
print(data)

Output:

[[1], [3], [5], [7]]

I don't know what the bigger picture is, so I can't comment on the use of this action.

Answered By - Jan Schmidt