I see this happening in a lot of online code examples, but when I parse my CSV file, all I get are strings as column indices, like
> data = Daru::DataFrame.from_csv('my_fancy_data.csv')
> data[:user_id]
IndexError: Specified index :user_id does not exist
> data['user_id']
=> #<Daru::Vector(42815)>
user_id
0 z0udgxc0lusu1gr4xj65
1 28080
2 28080
... ...