I have a dataframe signifying the temperature for three days for different regions in India. It's given in the following image.
[original\_dataframe](https://i.stack.imgur.com/2JCjA.png)

I need to generate another column in the same dataframe that concatenates the string values of the state and the city which is seen in 'Col5' as per the below image.

[output\_dataframe](https://i.stack.imgur.com/nyYso.png)

I'm aware of merging the values based on columns. But can something like be achieved using pandas or udf in python. Request your insights.