old_contents: import os
  import subprocess
  import sys
  
  from .identifiers import identifier
  
  
  def get_env_python():
      """
      I'm not proud of this hack, but I do believe it was necessary.
      """
      line = subprocess.check_output(
          "< .git/hooks/pre-commit grep 'ENV_PYTHON='",
          shell=True).splitlines()[0]
      return line.split('=')[-1].strip("'")
  
  
  def rreplace(s, old, new, occurrences=1):
      li = s.rsplit(old, occurrences)
      return new.join(li)
  
  
  def rename_merge_file(output):
      pwd = os.getcwd() + '/'
      loc = output.find('Created new merge migration ')
      path_start = output.find(pwd, loc)
      next_newline = output.find('\n', path_start)
      path_of_new_merge = output[path_start:next_newline]
      new_path = rreplace(path_of_new_merge, 'merge.py', identifier() + '_merge.py')
      os.rename(path_of_new_merge, new_path)
      return new_path
  
  
  def check_for_django_migrations(argv=None):
      output = subprocess.check_output(
          get_env_python() + ' manage.py makemigrations --merge  --noinput',
          shell=True)
  
      if 'No conflicts detected to merge' in output:
          return 0
      elif 'Created new merge migration ' in output:
          new_path = rename_merge_file(output)
          print 'Created new merge migration', new_path
          print 'Please add and commit it'
          return 1
      else:
          print 'Your migrations look like they could use a merge.'
          print 'psst, you can probably fix this by running'
          print '    ./manage.py makemigrations --merge'
          print "    (give it a weird name so it doesn't conflict when somebody else does this.)"
          print "Rather than 0012_merge.py, how about '0012_{}_merge.py'?".format(identifier())
          return 1
  
  if __name__ == '__main__':
      sys.exit(check_for_django_migrations())
  
new_contents: import os
  import subprocess
  import sys
  
  from .identifiers import identifier
  
  
  def get_env_python():
      """
      I'm not proud of this hack, but I do believe it was necessary.
      """
      line = subprocess.check_output(
          "< .git/hooks/pre-commit grep 'ENV_PYTHON='",
          shell=True).splitlines()[0]
      return line.split('=')[-1].strip("'")
  
  
  def rreplace(s, old, new, occurrences=1):
      li = s.rsplit(old, occurrences)
      return new.join(li)
  
  
  def rename_merge_file(output):
      pwd = os.getcwd() + '/'
      loc = output.find('Created new merge migration ')
      path_start = output.find(pwd, loc)
      next_newline = output.find('\n', path_start)
      path_of_new_merge = output[path_start:next_newline]
      new_path = rreplace(path_of_new_merge, 'merge.py', identifier() + '_merge.py')
      os.rename(path_of_new_merge, new_path)
      return new_path
  
  
  def check_for_django_migrations(argv=None):
      output = subprocess.check_output(
          get_env_python() + ' manage.py makemigrations --merge',
          shell=True)
  
      if 'No conflicts detected to merge' in output:
          return 0
      elif 'Created new merge migration ' in output:
          new_path = rename_merge_file(output)
          print 'Created new merge migration', new_path
          print 'Please add and commit it'
          return 1
      else:
          print 'Your migrations look like they could use a merge,'
          print "but it looks like you've elected not to do so?"
          return 1
  
  if __name__ == '__main__':
      sys.exit(check_for_django_migrations())
  
subject: Maintain the prompt to check if migrations conflict