Formatting numerical legend

I'm looking for a way to format the numerical legend (e.g. using integers) in matplotlib and haven't received any answer on [StackOverflow](https://stackoverflow.com/questions/52503899/format-number-in-legend-label-in-matplotlib). Thus, I wonder if there is a way to do so right now. If not, I wonder if this could be a possible feature to add in the future release. 
