# xarray.core.accessor_str.StringAccessor.islower

#### StringAccessor.islower()[[source]](https://github.com/pydata/xarray/blob/main/xarray/core/accessor_str.py#L976-L1000)

Check whether all characters in each string are lowercase.

* **Returns:**
  **islower** ([array](https://numpy.org/doc/stable/glossary.html#term-array) of [`bool`](https://docs.python.org/3/builtins/functions.html#bool)) – Array of boolean values with the same shape as the original array indicating whether all characters of each
  element of the string array are lowercase (True) or not (False).

### Examples

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```pycon
>>> da = xr.DataArray(["temperature", "HUMIDITY", "pREciPiTaTioN"], dims="x")
>>> da
<xarray.DataArray (x: 3)> Size: 156B
array(['temperature', 'HUMIDITY', 'pREciPiTaTioN'], dtype='<U13')
Dimensions without coordinates: x
>>> islower = da.str.islower()
>>> islower
<xarray.DataArray (x: 3)> Size: 3B
array([ True, False, False])
Dimensions without coordinates: x
```

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