To swap levels of a MultiIndex, use the swaplevel() method in Pandas. The levels to be swapped should be mentioned as arguments.
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], ['Peter', 'Chris', 'Andy', 'Jacob'], [50, 30, 40, 70]]
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=('rank', 'student', 'points'))
Swap levels of MultiIndex using swaplevel(). The 1st parameter is the first level of index to be swapped. The 2nd parameter is the second level of index to be swapped −
print("\nSwap levels in MultiIndex...\n",multiIndex.swaplevel(0,2))
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], ['Peter', 'Chris', 'Andy', 'Jacob'], [50, 30, 40, 70]] # 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=('rank', 'student', 'points')) # display the MultiIndex print("The MultiIndex...\n",multiIndex) # get the levels in MultiIndex print("\nThe levels in MultiIndex...\n",multiIndex.levels) # swap levels of MultiIndex using swaplevel() # The 1st parameter is the first level of index to be swapped # The 2nd parameter is the second level of index to be swapped print("\nSwap levels in MultiIndex...\n",multiIndex.swaplevel(0,2))
Output
This will produce the following output −
The MultiIndex... MultiIndex([(2, 'Peter', 50), (4, 'Chris', 30), (3, 'Andy', 40), (1, 'Jacob', 70)], names=['rank', 'student', 'points']) The levels in MultiIndex... [[1, 2, 3, 4], ['Andy', 'Chris', 'Jacob', 'Peter'], [30, 40, 50, 70]] Swap levels in MultiIndex... MultiIndex([(50, 'Peter', 2), (30, 'Chris', 4), (40, 'Andy', 3), (70, 'Jacob', 1)], names=['points', 'student', 'rank'])