# xarray.CFTimeIndex.putmask

#### CFTimeIndex.putmask(mask, value)[[source]](https://github.com/pydata/xarray/blob/main/xarray/../.pixi/envs/doc/lib/python3.15/site-packages/pandas/core/indexes/base.py#L5817-L5852)

Return a new Index of the values set with the mask.

Replaces elements of the Index where the corresponding mask entry is
`True`, returning a new Index rather than modifying in place.

* **Parameters:**
  * **mask** ([array-like](https://numpy.org/doc/stable/glossary.html#term-array_like) of [`bool`](https://docs.python.org/3/builtins/functions.html#bool)) – Array of booleans denoting where values should be replaced.
  * **value** ([scalar](../user-guide/terminology.html.md#term-scalar)) – Scalar value to use to fill holes (e.g. 0).
    This value cannot be a list-likes.
* **Returns:**
  [`Index`](https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.Index.html#pandas.Index) – A new Index of the values set with the mask.

#### SEE ALSO
[`numpy.putmask`](https://numpy.org/doc/stable/reference/generated/numpy.putmask.html#numpy.putmask)
: Changes elements of an array based on conditional and input values.

### Examples

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```pycon
>>> idx1 = pd.Index([1, 2, 3])
>>> idx2 = pd.Index([5, 6, 7])
>>> idx1.putmask([True, False, False], idx2)
Index([5, 2, 3], dtype='int64')
```

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