UserWarning: FixedFormatter should only be used together with FixedLocator
I have used for a long time small subroutines to format axes of charts I'm plotting. A couple of examples: def format_y_label_thousands(): # format y-axis tick labels formats ax = plt.gca() label_format = '{:,.0f}' ax.set_yticklabels([label_format.format(x) for x in ax.get_yticks().tolist()]) def format_y_label_percent(): # format y-axis tick labels formats