运行django报错

问题遇到的现象和发生背景

问题相关代码，请勿粘贴截图

运行结果及报错内容

我的解答思路和尝试过的方法

 File "manage.py", line 22, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/fanghongshi/PycharmProjects/djangoProject/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 364, in execute_from_command_line
    utility.execute()
  File "/Users/fanghongshi/PycharmProjects/djangoProject/venv/lib/python2.7/site-packages/django/core/management/__init__.py", line 308, in execute
    settings.INSTALLED_APPS
  File "/Users/fanghongshi/PycharmProjects/djangoProject/venv/lib/python2.7/site-packages/django/conf/__init__.py", line 56, in __getattr__
    self._setup(name)
  File "/Users/fanghongshi/PycharmProjects/djangoProject/venv/lib/python2.7/site-packages/django/conf/__init__.py", line 41, in _setup
    self._wrapped = Settings(settings_module)
  File "/Users/fanghongshi/PycharmProjects/djangoProject/venv/lib/python2.7/site-packages/django/conf/__init__.py", line 110, in __init__
    mod = importlib.import_module(self.SETTINGS_MODULE)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
  File "/Users/fanghongshi/PycharmProjects/djangoProject/djangoProject/settings.py", line 57, in <module>
    'DIRS': [BASE_DIR / 'templates']
TypeError: unsupported operand type(s) for /: 'str' and 'str'

我想要达到的结果

这样拼字符串会报错，换成下面这种方式
[BASE_DIR +'/templates']

这个列表里面语法有问题