You can easily get started with Excel. Python data analysis package pandas (VI): sorting

> I often listen to others Python How powerful in the data field , As a result, I studied for a long time , Even data processing is a death of trouble . Only later , It's not Python Data processing is powerful , But he has a data analysis artifact —— pandas

Preface

Sorting is a very basic data operation ,Excel The sorting function in is very flexible , You can sort rows and columns . Look at this article pandas How to do with Excel Same flexibility .

Excel Sort

Excel Sorting data in is very simple . as follows ：

• - Function card " data "," Sort " Button , The sort settings pop-up window appears
• - We can set the sort by field
• - First set up and press class Ascending , class If the same, press Chinese language and literature Grades are in ascending order
• - At the top right of the pop-up window , Yes " Set up " Button , You can choose to sort rows or columns

pandas Sort

pandas Sorting in is also very simple , And basically with Excel The process principle is consistent , After all, it's all data tools . as follows ：

• - DataFrame.sort_values(), You can sort them
• - The first parameter specifies the sort by key column
• - The second parameter specifies the ascending and descending sequence adopted by the key column corresponding to the first parameter
• - You can also set axis=1 , Sort by row ( There are few practical application scenarios )

Excel The sorting in can be customized , That is, let users customize the order ,pandas in , This function is not placed in sort_values To realize .

> actually Excel It also puts the custom sequence in a separate function

such as , hope Class according to "5,4,2,1,3,6,7" Sort , as follows ：

• - pandas You need to construct a column first Categorical , As an auxiliary column
• - Categorical The second parameter at instantiation specifies the order
• - Finally, call sort_values Method to complete custom sorting

> pandas Custom sorting in is relatively cumbersome , But we can completely encapsulate common operations by ourselves , You can also complete the custom sorting in one sentence

summary

• - DataFrame.sort_values() , Sort the data
• - The first parameter specifies the sort by key column
• - The second parameter specifies the lifting sequence
• - When a custom collation is required , It needs to be constructed Categorical Auxiliary column