Python Pandas - How to Sort MultiIndex

To create a MultiIndex, use the from_arrays() method. However, to sort MultiIndex, use the multiIndex.sortlevel(). method in Pandas.

At first, import the required libraries −

import pandas as pd

MultiIndex is a multi-level, or hierarchical, index object for pandas objects. Create arrays −

arrays = [[2, 4, 3, 1], ['John', 'Tim', 'Jacob', 'Chris']] 

The "names" parameter sets the names for each of the index levels. The from_arrays() is used to create a MultiInde −

multiIndex = pd.MultiIndex.from_arrays(arrays, names=('ranks', 'student'))

Sort MultiIndex. The default sorts at level 0 −

print("\nSort MultiIndex...\n",multiIndex.sortlevel()) 

Example

Following is the code −

import pandas as pd # MultiIndex is a multi-level, or hierarchical, index object for pandas objects # Create arrays arrays = [[2, 4, 3, 1], ['John', 'Tim', 'Jacob', 'Chris']] # The "names" parameter sets the names for each of the index levels # The from_arrays() is used to create a MultiIndex multiIndex = pd.MultiIndex.from_arrays(arrays, names=('ranks', 'student')) # display the MultiIndex print("The Multi-index...\n",multiIndex) # get the levels in MultiIndex print("\nThe levels in Multi-index...\n",multiIndex.levels) # Sort MultiIndex # The default sorts at level 0 print("\nSort MultiIndex...\n",multiIndex.sortlevel())

Output

This will produce the following output −

The Multi-index... MultiIndex([(2, 'John'),             (4, 'Tim'),             (3, 'Jacob'),             (1, 'Chris')],             names=['ranks', 'student']) The levels in Multi-index...    [[1, 2, 3, 4], ['Chris', 'Jacob', 'John', 'Tim']] Sort MultiIndex... (MultiIndex([(1, 'Chris'), (2, 'John'), (3, 'Jacob'), (4, 'Tim')], names=['ranks', 'student']), array([3, 0, 2, 1], dtype=int64))