About df['a column name'] [serial number]

As shown in the figure , When I select a column , Discovery index 0 It's normal , Indexes 1 It's a mistake , in consideration of df[‘latitude’] yes series type , I also searched series Index rules for , Just when I was desperate , Find out df1 Because of the preliminary treatment , The index is out of order , Indexes 1 non-existent , So wrong reporting . in other words , This method of re indexing by selecting the column name is realized by indexing the sequence number of the column .