def get_projection_class(projection=None):
 if (projection is None):
  projection = u'rectilinear'
 try:
  return projection_registry.get_projection_class(projection)
 except KeyError:
  raise ValueError((u"Unknown projection '%s'" % projection))

def get_projection_class ( projection = None ) : if ( projection is None ) : projection = u'rectilinear' try : return projection_registry . get_projection_class ( projection ) except KeyError : raise ValueError ( ( u"Unknown projection '%s'" % projection ) )
get a projection class from its name .