df.append() is not appending to the DataFrame

Question

I formulated this question about adding rows WITH index, but it is not yet clear to me how/why this happens when there are no indexes:

columnsList=[\'A\',\'B         


        

Answer 1

The statement data.append(sub_data) does not work on its own.

But the statement data=data.append(sub_data) will work

Assigning it back solved the issue for me. Good tip not available elsewhere.