code: def prettify_datetimes(datetimes, format="%b %Y", max_nonempty_strings=None, blank=''):
      
          # blank some labels to make sure they don't overlap
      datetimes = [make_datetime(d) for d in datetimes]
      datestrs = [d.strftime("%b %Y") for d in datetimes]
      if max_nonempty_strings:
          return thin_string_list(datestrs, max_nonempty_strings=max_nonempty_strings, blank=blank)
      return datestrs
docs: Designed for composing lists of strings suitable for pyplot axis labels
  
      Often the xtick spacing doesn't allow room for 100's of text labels, so this
      eliminates every other one, then every other one of those, until they fit.
  
      >>> thin_string_list(['x']*20, 5)  # doctring: +NORMALIZE_WHITESPACE
      ['x', '', '', '', 'x', '', '', '', 'x', '', '', '', 'x', '', '', '', 'x', '', '', '']