I need to convert the multiple columns in 1 columns.
For example, I have data like this:
Id Mercedes VW Nissan Audi
1 ClassA Polo N2 A4
2 NaN NaN N5 A2
I want to convert all of them into one:
Id Brand Model
1 Mercedes ClassA
1 VW Polo
1 Nissan N2
1 Audi A4
How i can do? Any idea?