pandas.Index.get_loc

Index.get_loc(key, method=None, tolerance=None)[source]

Get integer location, slice or boolean mask for requested label.

Parameters

key:label

method:{None, ‘pad’/’ffill’, ‘backfill’/’bfill’, ‘nearest’}, optional

• default: exact matches only.

• pad / ffill: find the PREVIOUS index value if no exact match.

• backfill / bfill: use NEXT index value if no exact match

• nearest: use the NEAREST index value if no exact match. Tied distances are broken by preferring the larger index value.

tolerance:int or float, optional

Maximum distance from index value for inexact matches. The value of the index at the matching location must satisfy the equation abs(index[loc] - key) <= tolerance.

Returns

loc:int if unique index, slice if monotonic index, else mask

Examples

>>> unique_index = pd.Index(list('abc'))
>>> unique_index.get_loc('b')
1

>>> monotonic_index = pd.Index(list('abbc'))
>>> monotonic_index.get_loc('b')
slice(1, 3, None)

>>> non_monotonic_index = pd.Index(list('abcb'))
>>> non_monotonic_index.get_loc('b')
array([False,  True, False,  True])