old_contents: #!/usr/bin/env python
  
  ###############################################################################
  # Copyright 2017 The Apollo Authors. 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.
  ###############################################################################
  
  import sys
  import rosbag
  from modules.localization.proto import localization_pb2
  
  if __name__ == '__main__':
      fbags = sys.argv[1:]
  
      f = open("path_"+ fbags[0].split('/')[-1] +".txt", 'w')
  
      for fbag in fbags:
          bag = rosbag.Bag(fbag)
          for topic, localization_pb, t in bag.read_messages(topics=['/apollo/localization/pose']):
              x = localization_pb.pose.position.x
              y = localization_pb.pose.position.y
              f.write(str(x) +","+ str(y) + "\n")
          bag.close()
new_contents: #!/usr/bin/env python
  
  ###############################################################################
  # Copyright 2017 The Apollo Authors. 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.
  ###############################################################################
  
  import sys
  import rosbag
  from modules.localization.proto import localization_pb2
  
  if __name__ == '__main__':
      fbags = sys.argv[1:]
  
      filename = "path_"+ fbags[0].split('/')[-1] +".txt"
      f = open(filename, 'w')
  
      for fbag in fbags:
          bag = rosbag.Bag(fbag)
          for topic, localization_pb, t in bag.read_messages(topics=['/apollo/localization/pose']):
              x = localization_pb.pose.position.x
              y = localization_pb.pose.position.y
              f.write(str(x) +","+ str(y) + "\n")
          bag.close()
      print ("File written to: %s" % filename)
  
subject: print more information