pandas.DataFrame.swaplevel#

DataFrame.swaplevel(i=-2,j=-1,axis=0)[source]#

Swap levels i and j in aMultiIndex.

Default is to swap the two innermost levels of the index.

Parameters:

i, jint or str

Levels of the indices to be swapped. Can pass level name as string.

axis{0 or ‘index’, 1 or ‘columns’}, default 0

The axis to swap levels on. 0 or ‘index’ for row-wise, 1 or‘columns’ for column-wise.

Returns:

DataFrame

DataFrame with levels swapped in MultiIndex.

Examples

>>>df=pd.DataFrame(...{"Grade":["A","B","A","C"]},...index=[...["Final exam","Final exam","Coursework","Coursework"],...["History","Geography","History","Geography"],...["January","February","March","April"],...],...)>>>df                                    GradeFinal exam  History     January      A            Geography   February     BCoursework  History     March        A            Geography   April        C

In the following example, we will swap the levels of the indices.Here, we will swap the levels column-wise, but levels can be swapped row-wisein a similar manner. Note that column-wise is the default behaviour.By not supplying any arguments for i and j, we swap the last and second tolast indices.

>>>df.swaplevel()                                    GradeFinal exam  January     History         A            February    Geography       BCoursework  March       History         A            April       Geography       C

By supplying one argument, we can choose which index to swap the lastindex with. We can for example swap the first index with the last one asfollows.

>>>df.swaplevel(0)                                    GradeJanuary     History     Final exam      AFebruary    Geography   Final exam      BMarch       History     Coursework      AApril       Geography   Coursework      C

We can also define explicitly which indices we want to swap by supplying valuesfor both i and j. Here, we for example swap the first and second indices.

>>>df.swaplevel(0,1)                                    GradeHistory     Final exam  January         AGeography   Final exam  February        BHistory     Coursework  March           AGeography   Coursework  April           C