text: from .scale import scale
  from copy import deepcopy
  
  class scale_y_discrete(scale):
      """
      Scale y axis as discrete values
  
      Parameters
      ----------
      breaks: list
          maps to ybreaks
      labels: list, dict
          maps to ytick_labels
  
      Examples
      --------
      >>> print ggplot(mtcars, aes('mpg', 'qsec')) + \
      ...     geom_point() + \
      ...     scale_y_discrete(breaks=[10,20,30],  \
      ...     labels=["horrible", "ok", "awesome"])
  
      """
      VALID_SCALES = ['name', 'limits', 'labels', 'breaks', 'trans']
      def __radd__(self, gg):
          gg = deepcopy(gg)
          if self.name:
              gg.ylab = self.name
          if self.limits:
              gg.ylimits = self.limits
          if self.breaks:
              gg.ybreaks = self.breaks
          if self.labels:
              gg.ytick_labels = self.labels
          return gg
  