AttributeError: у объекта 'module' нет атрибута 'SSLContext'

Question

Когда я использую flask run, я получаю эту ошибку.

Traceback (most recent call last):
  File "/Users/xuye/anaconda/bin/flask", line 11, in <module>
    sys.exit(main())
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/flask/cli.py", line 894, in main
    cli.main(args=args, prog_name=name)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/flask/cli.py", line 557, in main
    return super(FlaskGroup, self).main(*args, **kwargs)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/click/core.py", line 1135, in invoke
    sub_ctx = cmd.make_context(cmd_name, args, parent=ctx)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/click/core.py", line 641, in make_context
    self.parse_args(ctx, args)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/click/core.py", line 940, in parse_args
    value, args = param.handle_parse_result(ctx, opts, args)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/click/core.py", line 1477, in handle_parse_result
    self.callback, ctx, self, value)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/click/core.py", line 96, in invoke_param_callback
    return callback(ctx, param, value)
  File "/Users/xuye/anaconda/lib/python2.7/site-packages/flask/cli.py", line 693, in _validate_key
    is_context = isinstance(cert, ssl.SSLContext)
AttributeError: 'module' object has no attribute 'SSLContext'

Я искал и обновил свою версию Python до 2.7.15, но она не работает.