How do I set an index in a Pandas DataFrame?

How do I set an index in a Pandas DataFrame?

You can set an index in a Pandas DataFrame using the set_index() method. For example, df.set_index('column_name').

Can I set multiple columns as the index?

Yes, you can set multiple columns as the index by passing a list of column names, like this: df.set_index(['col1', 'col2']).

What happens to the original index?

The original index will be replaced by the new index. If you want to keep it, you can use the drop=False parameter.

How can I reset the index back to default?

You can reset the index using the reset_index() method. Just call df.reset_index() to revert to the default integer index.