Script to remove shape keys (not key blocks)

Does anyone know the Python code for removing shape keys?

Shape keys come in the form:
bpy.data.shape_keys[A].key_blocks[B]

The key blocks B can be removed using the ‘bpy.ops.object.shape_key_remove(all=True)’ command.

New shape keys A appear each time an animation script is run, and so build up over time, i.e.
>>> list(bpy.data.shape_keys)
[bpy.data.shape_keys[‘Key’], bpy.data.shape_keys[‘Key.001’], bpy.data.shape_keys[‘Key.002’], bpy.data.shape_keys[‘Key.003’], bpy.data.shape_keys[‘Key.004’], bpy.data.shape_keys[‘Key.005’], bpy.data.shape_keys[‘Key.006’], bpy.data.shape_keys[‘Key.007’], bpy.data.shape_keys[‘Key.008’], bpy.data.shape_keys[‘Key.009’], bpy.data.shape_keys[‘Key.010’], bpy.data.shape_keys[‘Key.011’], bpy.data.shape_keys[‘Key.012’], bpy.data.shape_keys[‘Key.013’]]

Does anyone know how to delete them?

Many thanks

Angus