old_contents: from __future__ import print_function
  
  import argparse
  
  
  class Requirement(object):
  
      def __init__(self):
          super(Requirement, self).__init__()
          self.value = None
          self.comments = []
  
      def __lt__(self, requirement):
          # \n means top of file comment, so always return True,
          # otherwise just do a string comparison with value.
          if self.value == b'\n':
              return True
          elif requirement.value == b'\n':
              return False
          else:
              return self.value < requirement.value
  
  
  def fix_requirements(f):
      requirements = []
      before = []
      after = []
  
      for line in f:
          before.append(line)
  
          # If the most recent requirement object has a value, then it's time to
          # start building the next requirement object.
          if not len(requirements) or requirements[-1].value is not None:
              requirements.append(Requirement())
  
          requirement = requirements[-1]
  
          # If we see a newline before any requirements, then this is a top of
          # file comment.
          if len(requirements) == 1 and line.strip() == b'':
              if len(requirement.comments) and requirement.comments[0].startswith(b'#'):
                  requirement.value = b'\n'
              else:
                  requirement.comments.append(line)
          elif line.startswith(b'#') or line.strip() == b'':
              requirement.comments.append(line)
          else:
              requirement.value = line
  
      for requirement in sorted(requirements):
          for comment in requirement.comments:
              after.append(comment)
          after.append(requirement.value)
  
      before_string = b''.join(before)
      after_string = b''.join(after)
  
      if before_string == after_string:
          return 0
      else:
          f.seek(0)
          f.write(after_string)
          f.truncate()
          return 1
  
  
  def fix_requirements_txt(argv=None):
      parser = argparse.ArgumentParser()
      parser.add_argument('filenames', nargs='*', help='Filenames to fix')
      args = parser.parse_args(argv)
  
      retv = 0
  
      for arg in args.filenames:
          with open(arg, 'rb+') as file_obj:
              retv |= fix_requirements(file_obj)
  
      return retv
  
new_contents: from __future__ import print_function
  
  import argparse
  
  
  class Requirement(object):
  
      def __init__(self):
          super(Requirement, self).__init__()
          self.value = None
          self.comments = []
  
      def __lt__(self, requirement):
          # \n means top of file comment, so always return True,
          # otherwise just do a string comparison with value.
          if self.value == b'\n':
              return True
          elif requirement.value == b'\n':
              return False
          else:
              return self.value < requirement.value
  
  
  def fix_requirements(f):
      requirements = []
      before = []
      after = []
  
      for line in f:
          before.append(line)
  
          # If the most recent requirement object has a value, then it's time to
          # start building the next requirement object.
          if not len(requirements) or requirements[-1].value is not None:
              requirements.append(Requirement())
  
          requirement = requirements[-1]
  
          # If we see a newline before any requirements, then this is a top of
          # file comment.
          if len(requirements) == 1 and line.strip() == b'':
              if len(requirement.comments) and requirement.comments[0].startswith(b'#'):
                  requirement.value = b'\n'
              else:
                  requirement.comments.append(line)
          elif line.startswith(b'#') or line.strip() == b'':
              requirement.comments.append(line)
          else:
              requirement.value = line
  
      for requirement in sorted(requirements):
          for comment in requirement.comments:
              after.append(comment)
          after.append(requirement.value)
  
      before_string = b''.join(before)
      after_string = b''.join(after)
  
      if before_string == after_string:
          return 0
      else:
          f.seek(0)
          f.write(after_string)
          f.truncate()
          return 1
  
  
  def fix_requirements_txt(argv=None):
      parser = argparse.ArgumentParser()
      parser.add_argument('filenames', nargs='*', help='Filenames to fix')
      args = parser.parse_args(argv)
  
      retv = 0
  
      for arg in args.filenames:
          with open(arg, 'rb+') as file_obj:
              ret_for_file = fix_requirements(file_obj)
  
              if ret_for_file:
                  print('Sorting {0}'.format(arg))
  
              retv |= ret_for_file
  
      return retv
  
subject: Print on requirements.txt failure