Return a new Index with elements of index not in other.
This is the set difference of two Index objects.
Whether to sort the resulting index. By default, the
values are attempted to be sorted, but any TypeError from
incomparable elements is caught by pandas.
None : Attempt to sort the result, but catch any TypeErrors
from comparing incomparable elements.
False : Do not sort the result.
New in version 0.24.0.
Changed in version 0.24.1: Changed the default value from True to None
(without change in behaviour).
>>> idx1 = pd.Index([2, 1, 3, 4])
>>> idx2 = pd.Index([3, 4, 5, 6])
Int64Index([1, 2], dtype='int64')
>>> idx1.difference(idx2, sort=False)
Int64Index([2, 1], dtype='int64')