code: def edit_release_notes():
          
          from tempfile import mkstemp
          import os
          import shlex
          import subprocess
  
          text_editor = shlex.split(os.environ.get('EDITOR', 'nano'))
  
          fd, tmp = mkstemp(prefix='bumpversion-')
          try:
              os.close(fd)
              with open(tmp, 'w') as f:
                  f.write(u"\n\n# Write release notes.\n"
                          u"# Lines starting with '#' will be ignored.")
              subprocess.check_call(text_editor + [tmp])
              with open(tmp, 'r') as f:
                  changes = "".join(
                      l for l in f.readlines() if not l.startswith('#'))
          finally:
              os.remove(tmp)
          return changes
docs: Use the default text $EDITOR to write release notes.
          If $EDITOR is not set, use 'nano'.