# xarray.testing.strategies.dimension_sizes

### xarray.testing.strategies.dimension_sizes(, dim_names=text(alphabet=characters(max_codepoint=383, categories=['L', 'N']), min_size=1, max_size=5), min_dims=0, max_dims=3, min_side=1, max_side=None)[[source]](https://github.com/pydata/xarray/blob/main/xarray/testing/strategies.py#L166-L210)

Generates an arbitrary mapping from dimension names to lengths.

Requires the hypothesis package to be installed.

* **Parameters:**
  * **dim_names** (`strategy generating strings`, *optional*) – Strategy for generating dimension names.
    Defaults to the names strategy.
  * **min_dims** ([`int`](https://docs.python.org/3/builtins/functions.html#int), *optional*) – Minimum number of dimensions in generated list.
    Default is 1.
  * **max_dims** ([`int`](https://docs.python.org/3/builtins/functions.html#int), *optional*) – Maximum number of dimensions in generated list.
    Default is 3.
  * **min_side** ([`int`](https://docs.python.org/3/builtins/functions.html#int), *optional*) – Minimum size of a dimension.
    Default is 1.
  * **max_side** ([`int`](https://docs.python.org/3/builtins/functions.html#int), *optional*) – Minimum size of a dimension.
    Default is min_length + 5.

#### SEE ALSO
[Hypothesis testing](../user-guide/testing.html.md#testing-hypothesis)