Python2的Flask坑（一）--Set the secret_key on the application to something unique and secret

增加这行代码，值可以随便写

app.secret_key = "sdkfjlqjluio23u429037907!@#!@#!@@" 

使用session、flash需要secret_key

RuntimeError
RuntimeError: the session is unavailable because no secret key was set.  Set the secret_key on the application to something unique and secret.

Traceback (most recent call last)
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/home/python/Desktop/Flask/FLask_test3/test5_tempvar.py", line 11, in index
flash(u"闪现消息1")
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/helpers.py", line 366, in flash
session['_flashes'] = flashes
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/werkzeug/local.py", line 350, in __setitem__
self._get_current_object()[key] = value
File "/home/python/.virtualenvs/Flask_py/lib/python2.7/site-packages/flask/sessions.py", line 126, in _fail
raise RuntimeError('the session is unavailable because no secret '
RuntimeError: the session is unavailable because no secret key was set. Set the secret_key on the application to something unique and secret.