I have a big dataframe with the format
col1 col2 val1 val2
[0]A B 0.8 0.1
[1]B A 0.8 0.1
[2]A C 0.3 0.9
[3]A D 0.2 0.8
[4]D A 0.2 0.8
As you can see, some rows are duplicated with only col1 and col2 reversed. For instance, row 1 is duplicate of row 0, and row 4 is duplicate of row 3. Can you drop the duplicates based on the match of col1:col2 being equal to those of col2:col1?