old_contents: from __future__ import print_function, absolute_import, division
  
  
  class Error(Exception):
      """Base Cu2Qu exception class for all other errors."""
  
  
  class ApproxNotFoundError(Error):
      def __init__(self, curve):
          message = "no approximation found: %s" % curve
          super(Error, self).__init__(message)
          self.curve = curve
  
  
  class UnequalZipLengthsError(Error):
      pass
  
  
  class IncompatibleGlyphsError(Error):
      def __init__(self, glyphs):
          assert len(glyphs) > 1
          self.glyphs = glyphs
          names = set(repr(g.name) for g in glyphs)
          if len(names) > 1:
              self.combined_name = "{%s}" % ", ".join(sorted(names))
          else:
              self.combined_name = names.pop()
  
      def __repr__(self):
          return "<%s %s>" % (type(self).__name__, self.combined_name)
  
  
  class IncompatibleSegmentNumberError(IncompatibleGlyphsError):
      def __str__(self):
          return "Glyphs named %s have different number of segments" % (
              self.combined_name
          )
  
  
  class IncompatibleSegmentTypesError(IncompatibleGlyphsError):
      def __init__(self, glyphs, segments):
          IncompatibleGlyphsError.__init__(self, glyphs)
          self.segments = segments
  
      def __str__(self):
          lines = []
          ndigits = len(str(max(self.segments)))
          for i, tags in sorted(self.segments.items()):
              lines.append(
                  "%s: (%s)" % (str(i).rjust(ndigits), ", ".join(repr(t) for t in tags))
              )
          return "Glyphs named %s have incompatible segment types:\n  %s" % (
              self.combined_name,
              "\n  ".join(lines),
          )
  
  
  class IncompatibleFontsError(Error):
      def __init__(self, glyph_errors):
          self.glyph_errors = glyph_errors
  
      def __str__(self):
          return "fonts contains incompatible glyphs: %s" % (
              ", ".join(repr(g) for g in sorted(self.glyph_errors.keys()))
          )
  
new_contents: from __future__ import print_function, absolute_import, division
  
  
  class Error(Exception):
      """Base Cu2Qu exception class for all other errors."""
  
  
  class ApproxNotFoundError(Error):
      def __init__(self, curve):
          message = "no approximation found: %s" % curve
          super(Error, self).__init__(message)
          self.curve = curve
  
subject: remove unused exceptions