pandas.Series.case_when

Series.case_when(caselist)

Replace values where the conditions are True.

Added in version 2.2.0.

Parameters:

caselistA list of tuples of conditions and expected replacements

Takes the form: (condition0, replacement0), (condition1, replacement1), … . condition should be a 1-D boolean array-like object or a callable. If condition is a callable, it is computed on the Series and should return a boolean Series or array. The callable must not change the input Series (though pandas doesn`t check it). replacement should be a 1-D array-like object, a scalar or a callable. If replacement is a callable, it is computed on the Series and should return a scalar or Series. The callable must not change the input Series (though pandas doesn`t check it).

Returns:

Series

A new Series with values replaced based on the provided conditions.

See also

Series.mask

Replace values where the condition is True.

Examples

>>> c = pd.Series([6, 7, 8, 9], name="c")
>>> a = pd.Series([0, 0, 1, 2])
>>> b = pd.Series([0, 3, 4, 5])

>>> c.case_when(
...     caselist=[
...         (a.gt(0), a),  # condition, replacement
...         (b.gt(0), b),
...     ]
... )
0    6
1    3
2    1
3    2
Name: c, dtype: int64