Use doctests

Author: dstansby

docs/user-guide/async.rst

@@ -9,30 +9,28 @@ API enables concurrent I/O and parallel processing using a managed thread pool.
 When operating in an async context, it can be used to provide asynchronous
 access to Zarr data.
 
-The usage of the async API mirrors the synchronous API.
-
-.. ipython:: python
-
-   import asyncio
-   import numpy as np
-   import zarr.api.asynchronous as async_zarr
-
-   # create a new group using the asynchronous API
-   root = await async_zarr.create_group(attributes={'foo': 'bar'})
-   root
-   # create an array using the AsyncGroup
-   z = await root.create_array(name='foo', shape=(100, ), chunks=(5, ), dtype=np.uint32)
-   z
-   # set and get items
-   await z.setitem((slice(None), ), np.arange(0, 100, dtype=z.dtype))
-   # set a single item
-   await z.setitem((7,), -99)
-   # set a range to a constant value using a slice
-   await z.setitem(slice(0, 3), -1)
-   # get a slice of the array
-   await z.getitem((slice(0, 5), ))
-   # gather multiple items concurrently
-   await asyncio.gather(z.getitem(slice(0, 5)), z.getitem(slice(6, 10)))
+The usage of the async API mirrors the synchronous API::
+
+   >>> import asyncio
+   >>> import numpy as np
+   >>> import zarr.api.asynchronous as async_zarr
+   >>>
+   >>> # create a new group using the asynchronous API
+   >>> root = await async_zarr.create_group(attributes={'foo': 'bar'})
+   >>> root
+   >>> # create an array using the AsyncGroup
+   >>> z = await root.create_array(name='foo', shape=(100, ), chunks=(5, ), dtype=np.uint32)
+   >>> z
+   >>> # set and get items
+   >>> await z.setitem((slice(None), ), np.arange(0, 100, dtype=z.dtype))
+   >>> # set a single item
+   >>> await z.setitem((7,), -99)
+   >>> # set a range to a constant value using a slice
+   >>> await z.setitem(slice(0, 3), -1)
+   >>> # get a slice of the array
+   >>> await z.getitem((slice(0, 5), ))
+   >>> # gather multiple items concurrently
+   >>> await asyncio.gather(z.getitem(slice(0, 5)), z.getitem(slice(6, 10)))
 
 See the API docs for more details: