I am able to set data source encoding through this answer to Setting character encoding for all layers at once using PyQGIS? and now i want to list all the datasource encodig types. how it is possible i have also check official API but nothing found!
for layer in QgsMapLayerRegistry.instance().mapLayers().values():
layer.setProviderEncoding(u'UTF-8')
layer.dataProvider().setEncoding(u'UTF-8')
print layer.name(), layer.dataProvider().encoding()