old_contents: # Copyright 2015 Google Inc. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from __future__ import print_function, division, absolute_import, unicode_literals
  
  import sys
  import argparse
  
  import glyphsLib
  
  
  description = """\n
  Converts a Glyphs.app source file into UFO masters
  or UFO instances and MutatorMath designspace.
  """
  
  
  def parse_options(args):
      parser = argparse.ArgumentParser(description=description)
      parser.add_argument("--version", action="version",
                          version='glyphsLib %s' % (glyphsLib.__version__))
      parser.add_argument("-g", "--glyphs", metavar="GLYPHS", required=True,
                          help="Glyphs file to convert.")
      parser.add_argument("-m", "--masters", metavar="MASTERS",
                          default="master_ufo",
                          help="Ouput masters UFO to folder MASTERS. "
                               "(default: %(default)s)")
      parser.add_argument("-n", "--instances", metavar="INSTANCES", nargs="?",
                          const="instance_ufo", default=None,
                          help="Output and generate interpolated instances UFO "
                               "to folder INSTANCES. "
                               "(default: %(const)s)")
      parser.add_argument("-R", "--no-round", action="store_false",
                          help="Round geometry to integers")
      options = parser.parse_args(args)
      return options
  
  
  def main(args=None):
      opt = parse_options(args)
      if opt.glyphs is not None:
          if opt.instances is None:
              glyphsLib.build_masters(opt.glyphs, opt.masters)
          else:
              glyphsLib.build_instances(opt.glyphs, opt.masters, opt.instances,
                                        round_geometry=opt.no_round)
  
  if __name__ == '__main__':
      main(sys.argv[1:])
  
new_contents: # Copyright 2015 Google Inc. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from __future__ import print_function, division, absolute_import, unicode_literals
  
  import sys
  import argparse
  
  import glyphsLib
  
  
  description = """\n
  Converts a Glyphs.app source file into UFO masters
  or UFO instances and MutatorMath designspace.
  """
  
  
  def parse_options(args):
      parser = argparse.ArgumentParser(description=description)
      parser.add_argument("--version", action="version",
                          version='glyphsLib %s' % (glyphsLib.__version__))
      parser.add_argument("-g", "--glyphs", metavar="GLYPHS", required=True,
                          help="Glyphs file to convert.")
      parser.add_argument("-m", "--masters", metavar="MASTERS",
                          default="master_ufo",
                          help="Ouput masters UFO to folder MASTERS. "
                               "(default: %(default)s)")
      parser.add_argument("-n", "--instances", metavar="INSTANCES", nargs="?",
                          const="instance_ufo", default=None,
                          help="Output and generate interpolated instances UFO "
                               "to folder INSTANCES. "
                               "(default: %(const)s)")
      parser.add_argument("-r", "--round-instances", action="store_true",
                          help="Apply integer rounding to all geometry when "
                               "interpolating")
      options = parser.parse_args(args)
      return options
  
  
  def main(args=None):
      opt = parse_options(args)
      if opt.glyphs is not None:
          if opt.instances is None:
              glyphsLib.build_masters(opt.glyphs, opt.masters)
          else:
              glyphsLib.build_instances(opt.glyphs, opt.masters, opt.instances,
                                        round_geometry=opt.round_instances)
  
  if __name__ == '__main__':
      main(sys.argv[1:])
  
subject: rename --no-round to --round-instances (positive), False by default