pandas.DataFrame.xs

DataFrame.xs(key, axis=0, level=None, drop_level=True)

Return cross-section from the Series/DataFrame.

This method takes a key argument to select data at a particular level of a MultiIndex.

Parameters:

keylabel or tuple of label

Label contained in the index, or partially in a MultiIndex.

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

Axis to retrieve cross-section on.

levelobject, defaults to first n levels (n=1 or len(key))

In case of a key partially contained in a MultiIndex, indicate which levels are used. Levels can be referred by label or position.

drop_levelbool, default True

If False, returns object with same levels as self.

Returns:

Series or DataFrame

Cross-section from the original Series or DataFrame corresponding to the selected index levels.

See also

DataFrame.loc

Access a group of rows and columns by label(s) or a boolean array.

DataFrame.iloc

Purely integer-location based indexing for selection by position.

Notes

xs can not be used to set values.

MultiIndex Slicers is a generic way to get/set values on any level or levels. It is a superset of xs functionality, see MultiIndex Slicers.

Examples

>>> d = {
...     "num_legs": [4, 4, 2, 2],
...     "num_wings": [0, 0, 2, 2],
...     "class": ["mammal", "mammal", "mammal", "bird"],
...     "animal": ["cat", "dog", "bat", "penguin"],
...     "locomotion": ["walks", "walks", "flies", "walks"],
... }
>>> df = pd.DataFrame(data=d)
>>> df = df.set_index(["class", "animal", "locomotion"])
>>> df
                           num_legs  num_wings
class  animal  locomotion
mammal cat     walks              4          0
       dog     walks              4          0
       bat     flies              2          2
bird   penguin walks              2          2

Get values at specified index

>>> df.xs("mammal")
                   num_legs  num_wings
animal locomotion
cat    walks              4          0
dog    walks              4          0
bat    flies              2          2

Get values at several indexes

>>> df.xs(("mammal", "dog", "walks"))
num_legs     4
num_wings    0
Name: (mammal, dog, walks), dtype: int64

Get values at specified index and level

>>> df.xs("cat", level=1)
                   num_legs  num_wings
class  locomotion
mammal walks              4          0

Get values at several indexes and levels

>>> df.xs(("bird", "walks"), level=[0, "locomotion"])
         num_legs  num_wings
animal
penguin         2          2

Get values at specified column and axis

>>> df.xs("num_wings", axis=1)
class   animal   locomotion
mammal  cat      walks         0
        dog      walks         0
        bat      flies         2
bird    penguin  walks         2
Name: num_wings, dtype: int64