polars.Series.replace#

Series.replace(old: IntoExpr | Sequence[Any] | Mapping[Any, Any], new: IntoExpr | Sequence[Any] | NoDefault = <no_default>) → Self[source]#

Replace values by different values of the same data type.

Parameters:

old: Value or sequence of values to replace. Also accepts a mapping of values to their replacement as syntactic sugar for replace(old=Series(mapping.keys()), new=Series(mapping.values())).
new: Value or sequence of values to replace by. Length must match the length of old or have length 1.

See also

replace_strict
str.replace

Examples

Replace a single value by another value. Values that were not replaced remain unchanged.

>>> s = pl.Series([1, 2, 2, 3])
>>> s.replace(2, 100)
shape: (4,)
Series: '' [i64]
[
    1
    100
    100
    3
]

Replace multiple values by passing sequences to the old and new parameters.

>>> s.replace([2, 3], [100, 200])
shape: (4,)
Series: '' [i64]
[
    1
    100
    100
    200
]

Passing a mapping with replacements is also supported as syntactic sugar.

>>> mapping = {2: 100, 3: 200}
>>> s.replace(mapping)
shape: (4,)
Series: '' [i64]
[
    1
    100
    100
    200
]

The original data type is preserved when replacing by values of a different data type. Use replace_strict() to replace and change the return data type.

>>> s = pl.Series(["x", "y", "z"])
>>> mapping = {"x": 1, "y": 2, "z": 3}
>>> s.replace(mapping)
shape: (3,)
Series: '' [str]
[
    "1"
    "2"
    "3"
]