[1.8.x] Documented gdal DataSource encoding parameter

additional fields (:class:`Field`) of data that may be associated with

each feature in that layer.

.. class:: DataSource(ds_input)

.. class:: DataSource(ds_input, [encoding='utf-8'])

   The constructor for ``DataSource`` just a single parameter: the path of

   The constructor for ``DataSource`` only requires one parameter: the path of

   the file you want to read. However, OGR

   also supports a variety of more complex data sources, including

   databases, that may be accessed by passing a special name string instead

   instance gives the OGR name of the underlying data source that it is

   using.

   The optional ``encoding`` parameter allows you to

   specify a non-standard encoding of the strings in the source. This is

   typically useful when you obtain ``DjangoUnicodeDecodeError`` exceptions

   while reading field values.

   Once you've created your ``DataSource``, you can find out how many

   layers of data it contains by accessing the :attr:`layer_count` property,

   or (equivalently) by using the ``len()`` function.  For information on