ndb.KeyProperty 的默认值
Default value for ndb.KeyProperty
我有这两个型号：
#################
### Usergroup ###
#################
class Usergroup(ndb.Model):
group_name = ndb.StringProperty(indexed = False, required = True)
is_admin_group = ndb.BooleanProperty(indexed = False, required = False, default = False)
############
### User ###
############
class User(ndb.Model):
fb_id = ndb.StringProperty(indexed = True, required = True)
fb_access_token = ndb.TextProperty(indexed = False, required = True)
email = ndb.StringProperty(indexed = True, required = True)
first_name = ndb.StringProperty(indexed = False, required = True)
last_name = ndb.StringProperty(indexed = False, required = True)
gender = ndb.StringProperty(indexed = False)
group_key = ndb.KeyProperty(indexed = False, required = False, kind = Usergroup, default = ndb.Key(Usergroup, 'member'))
join_date = ndb.DateTimeProperty(indexed = True, auto_now_add = True)
last_login = ndb.DateTimeProperty(indexed = True, auto_now_add = True, auto_now = False)
@app.route('/user/login', methods=['POST'])
def user_login():
me = exchange_token_me(request.form['accessToken'])
if me is not False:
user = user_find_or_register(me)
if user is not None:
register_session(user)
return 'success'
return 'error'
def user_find_or_register(user):
qry = User.query(User.fb_id == user['id'])
existing_user = qry.get()
if existing_user is not None:
existing_user.fb_access_token = user['access_token']
existing_user.fb_id = user['id']
existing_user.email = user['email']
existing_user.last_login = datetime.datetime.now()
existing_user.put()
return existing_user
new_user = User()
new_user.fb_id = user['id']
new_user.fb_access_token = user['access_token']
new_user.email = user['email']
new_user.first_name = user['first_name']
new_user.last_name = user['last_name']
new_user.gender = user['gender']
new_user.last_login = datetime.datetime.now()
#new_user.group_key = ndb.key(Usergroup, 'member')
key = new_user.put()
saved_user = key.get()
#key.delete() # DEBUG
if saved_user is not None:
return saved_user
def register_session(user):
session['fb_id'] = user.fb_id
session['first_name'] = user.first_name
session['last_name'] = user.last_name
session['group_key'] = user.group_key
session['loggedin'] = True
用户组模型有一个小的唯一字符串作为实体键。已经有一个 Key 为 'member'
的用户组
每当我们 create/save 一个用户时，它应该使用 'member' 用户组的密钥，但我们却得到这个错误：
TypeError: Key('Usergroup', 'member') 不是 JSON 可序列化的
回溯：
ERROR 2016-10-18 14:32:40,572 app.py:1587] Exception on /user/login [POST]
Traceback (most recent call last):
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1988, in wsgi_app
response = self.full_dispatch_request()
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1643, in full_dispatch_request
response = self.process_response(response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1864, in process_response
self.save_session(ctx.session, response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 926, in save_session
return self.session_interface.save_session(self, session, response)
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 359, in save_session
val = self.get_signing_serializer(app).dumps(dict(session))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 565, in dumps
payload = want_bytes(self.dump_payload(obj))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 847, in dump_payload
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 550, in dump_payload
return want_bytes(self.serializer.dumps(obj))
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 85, in dumps
return json.dumps(_tag(value), separators=(',', ':'))
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 126, in dumps
rv = _json.dumps(obj, **kwargs)
File "/usr/lib/python2.7/json/__init__.py", line 251, in dumps
sort_keys=sort_keys, **kw).encode(obj)
File "/usr/lib/python2.7/json/encoder.py", line 209, in encode
chunks = list(chunks)
File "/usr/lib/python2.7/json/encoder.py", line 434, in _iterencode
for chunk in _iterencode_dict(o, _current_indent_level):
File "/usr/lib/python2.7/json/encoder.py", line 408, in _iterencode_dict
for chunk in chunks:
File "/usr/lib/python2.7/json/encoder.py", line 442, in _iterencode
o = _default(o)
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 83, in default
return _json.JSONEncoder.default(self, o)
File "/usr/lib/python2.7/json/encoder.py", line 184, in default
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: Key('Usergroup', 'member') is not JSON serializable
ERROR 2016-10-18 14:32:40,593 main.py:178] An error occurred during a request.
Traceback (most recent call last):
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1988, in wsgi_app
response = self.full_dispatch_request()
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1643, in full_dispatch_request
response = self.process_response(response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1864, in process_response
self.save_session(ctx.session, response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 926, in save_session
return self.session_interface.save_session(self, session, response)
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 359, in save_session
val = self.get_signing_serializer(app).dumps(dict(session))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 565, in dumps
payload = want_bytes(self.dump_payload(obj))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 847, in dump_payload
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 550, in dump_payload
return want_bytes(self.serializer.dumps(obj))
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 85, in dumps
return json.dumps(_tag(value), separators=(',', ':'))
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 126, in dumps
rv = _json.dumps(obj, **kwargs)
File "/usr/lib/python2.7/json/__init__.py", line 251, in dumps
sort_keys=sort_keys, **kw).encode(obj)
File "/usr/lib/python2.7/json/encoder.py", line 209, in encode
chunks = list(chunks)
File "/usr/lib/python2.7/json/encoder.py", line 434, in _iterencode
for chunk in _iterencode_dict(o, _current_indent_level):
File "/usr/lib/python2.7/json/encoder.py", line 408, in _iterencode_dict
for chunk in chunks:
File "/usr/lib/python2.7/json/encoder.py", line 442, in _iterencode
o = _default(o)
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 83, in default
return _json.JSONEncoder.default(self, o)
File "/usr/lib/python2.7/json/encoder.py", line 184, in default
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: Key('Usergroup', 'member') is not JSON serializable
INFO 2016-10-18 14:32:40,610 module.py:788] default: "POST /user/login HTTP/1.1" 500 27
更新：
Dan 发现问题后，解决方案在以下函数中：
def register_session(user):
session['fb_id'] = user.fb_id
session['first_name'] = user.first_name
session['last_name'] = user.last_name
session['group_key'] = user.group_key.id() # Thanks Dan
session['loggedin'] = True
FWIW，使用您的代码进行快速测试 models.py 表明它工作正常，至少在开发服务器上是这样：
from models import User
user = User(email='email', username='username')
user.put()
制作：
这甚至在没有 Usergroup 实体的情况下也能奏效 - 键可以在没有匹配实体的情况下存在。当然，尝试在数据存储查看器中跟随 link 到用户组失败：
Traceback (most recent call last):
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1536, in __call__
rv = self.handle_exception(request, response, e)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1530, in __call__
rv = self.router.dispatch(request, response)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1278, in default_dispatcher
return route.handler_adapter(request, response)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1102, in __call__
return handler.dispatch()
File "/home/usr_local/google_appengine/google/appengine/tools/devappserver2/admin/admin_request_handler.py", line 96, in dispatch
super(AdminRequestHandler, self).dispatch()
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 572, in dispatch
return self.handle_exception(e, self.app.debug)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 570, in dispatch
return method(*args, **kwargs)
File "/home/usr_local/google_appengine/google/appengine/tools/devappserver2/admin/datastore_viewer.py", line 741, in get
entities = [datastore.Get(entity_key)]
File "/home/usr_local/google_appengine/google/appengine/api/datastore.py", line 671, in Get
return GetAsync(keys, **kwargs).get_result()
File "/home/usr_local/google_appengine/google/appengine/api/apiproxy_stub_map.py", line 613, in get_result
return self.__get_result_hook(self)
File "/home/usr_local/google_appengine/google/appengine/datastore/datastore_rpc.py", line 1717, in __get_hook
entities = extra_hook(entities)
File "/home/usr_local/google_appengine/google/appengine/api/datastore.py", line 640, in local_extra_hook
raise datastore_errors.EntityNotFoundError()
EntityNotFoundError
因此您可能想要显示创建实体的实际代码和完整的回溯，可能还有其他事情正在发生。
您的回溯表明问题不是创建实体，而是保存您的会话：
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 926, in save_session
return self.session_interface.save_session(self, session, response)
您似乎在会话内容中包含了关键对象（可能是通过包含整个 User 实体？），这就是导致失败的原因。为此，需要序列化密钥，您可以为此使用 key.urlsafe()。有关示例，请参见此答案：
如果您确实在会话中包含了整个 User 实体，您可以只包含它的 urlsafe 密钥。
是的，这就是问题的根源：
session['group_key'] = user.group_key
改为：
session['group_key'] = user.group_key.urlsafe()
您将像这样检索它：
urlsafe_key = session.get('group_key')
if urlsafe_key:
group_key = ndb.Key(urlsafe=urlsafe_key)
我有这两个型号：
#################
### Usergroup ###
#################
class Usergroup(ndb.Model):
group_name = ndb.StringProperty(indexed = False, required = True)
is_admin_group = ndb.BooleanProperty(indexed = False, required = False, default = False)
############
### User ###
############
class User(ndb.Model):
fb_id = ndb.StringProperty(indexed = True, required = True)
fb_access_token = ndb.TextProperty(indexed = False, required = True)
email = ndb.StringProperty(indexed = True, required = True)
first_name = ndb.StringProperty(indexed = False, required = True)
last_name = ndb.StringProperty(indexed = False, required = True)
gender = ndb.StringProperty(indexed = False)
group_key = ndb.KeyProperty(indexed = False, required = False, kind = Usergroup, default = ndb.Key(Usergroup, 'member'))
join_date = ndb.DateTimeProperty(indexed = True, auto_now_add = True)
last_login = ndb.DateTimeProperty(indexed = True, auto_now_add = True, auto_now = False)
@app.route('/user/login', methods=['POST'])
def user_login():
me = exchange_token_me(request.form['accessToken'])
if me is not False:
user = user_find_or_register(me)
if user is not None:
register_session(user)
return 'success'
return 'error'
def user_find_or_register(user):
qry = User.query(User.fb_id == user['id'])
existing_user = qry.get()
if existing_user is not None:
existing_user.fb_access_token = user['access_token']
existing_user.fb_id = user['id']
existing_user.email = user['email']
existing_user.last_login = datetime.datetime.now()
existing_user.put()
return existing_user
new_user = User()
new_user.fb_id = user['id']
new_user.fb_access_token = user['access_token']
new_user.email = user['email']
new_user.first_name = user['first_name']
new_user.last_name = user['last_name']
new_user.gender = user['gender']
new_user.last_login = datetime.datetime.now()
#new_user.group_key = ndb.key(Usergroup, 'member')
key = new_user.put()
saved_user = key.get()
#key.delete() # DEBUG
if saved_user is not None:
return saved_user
def register_session(user):
session['fb_id'] = user.fb_id
session['first_name'] = user.first_name
session['last_name'] = user.last_name
session['group_key'] = user.group_key
session['loggedin'] = True
用户组模型有一个小的唯一字符串作为实体键。已经有一个 Key 为 'member'
的用户组每当我们 create/save 一个用户时，它应该使用 'member' 用户组的密钥，但我们却得到这个错误：
TypeError: Key('Usergroup', 'member') 不是 JSON 可序列化的
回溯：
ERROR 2016-10-18 14:32:40,572 app.py:1587] Exception on /user/login [POST]
Traceback (most recent call last):
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1988, in wsgi_app
response = self.full_dispatch_request()
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1643, in full_dispatch_request
response = self.process_response(response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1864, in process_response
self.save_session(ctx.session, response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 926, in save_session
return self.session_interface.save_session(self, session, response)
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 359, in save_session
val = self.get_signing_serializer(app).dumps(dict(session))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 565, in dumps
payload = want_bytes(self.dump_payload(obj))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 847, in dump_payload
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 550, in dump_payload
return want_bytes(self.serializer.dumps(obj))
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 85, in dumps
return json.dumps(_tag(value), separators=(',', ':'))
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 126, in dumps
rv = _json.dumps(obj, **kwargs)
File "/usr/lib/python2.7/json/__init__.py", line 251, in dumps
sort_keys=sort_keys, **kw).encode(obj)
File "/usr/lib/python2.7/json/encoder.py", line 209, in encode
chunks = list(chunks)
File "/usr/lib/python2.7/json/encoder.py", line 434, in _iterencode
for chunk in _iterencode_dict(o, _current_indent_level):
File "/usr/lib/python2.7/json/encoder.py", line 408, in _iterencode_dict
for chunk in chunks:
File "/usr/lib/python2.7/json/encoder.py", line 442, in _iterencode
o = _default(o)
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 83, in default
return _json.JSONEncoder.default(self, o)
File "/usr/lib/python2.7/json/encoder.py", line 184, in default
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: Key('Usergroup', 'member') is not JSON serializable
ERROR 2016-10-18 14:32:40,593 main.py:178] An error occurred during a request.
Traceback (most recent call last):
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1988, in wsgi_app
response = self.full_dispatch_request()
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1643, in full_dispatch_request
response = self.process_response(response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 1864, in process_response
self.save_session(ctx.session, response)
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 926, in save_session
return self.session_interface.save_session(self, session, response)
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 359, in save_session
val = self.get_signing_serializer(app).dumps(dict(session))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 565, in dumps
payload = want_bytes(self.dump_payload(obj))
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 847, in dump_payload
json = super(URLSafeSerializerMixin, self).dump_payload(obj)
File "/var/www/mywebsite/public_html/lib/itsdangerous.py", line 550, in dump_payload
return want_bytes(self.serializer.dumps(obj))
File "/var/www/mywebsite/public_html/lib/flask/sessions.py", line 85, in dumps
return json.dumps(_tag(value), separators=(',', ':'))
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 126, in dumps
rv = _json.dumps(obj, **kwargs)
File "/usr/lib/python2.7/json/__init__.py", line 251, in dumps
sort_keys=sort_keys, **kw).encode(obj)
File "/usr/lib/python2.7/json/encoder.py", line 209, in encode
chunks = list(chunks)
File "/usr/lib/python2.7/json/encoder.py", line 434, in _iterencode
for chunk in _iterencode_dict(o, _current_indent_level):
File "/usr/lib/python2.7/json/encoder.py", line 408, in _iterencode_dict
for chunk in chunks:
File "/usr/lib/python2.7/json/encoder.py", line 442, in _iterencode
o = _default(o)
File "/var/www/mywebsite/public_html/lib/flask/json.py", line 83, in default
return _json.JSONEncoder.default(self, o)
File "/usr/lib/python2.7/json/encoder.py", line 184, in default
raise TypeError(repr(o) + " is not JSON serializable")
TypeError: Key('Usergroup', 'member') is not JSON serializable
INFO 2016-10-18 14:32:40,610 module.py:788] default: "POST /user/login HTTP/1.1" 500 27
更新： Dan 发现问题后，解决方案在以下函数中：
def register_session(user):
session['fb_id'] = user.fb_id
session['first_name'] = user.first_name
session['last_name'] = user.last_name
session['group_key'] = user.group_key.id() # Thanks Dan
session['loggedin'] = True
FWIW，使用您的代码进行快速测试 models.py 表明它工作正常，至少在开发服务器上是这样：
from models import User
user = User(email='email', username='username')
user.put()
制作：
这甚至在没有 Usergroup 实体的情况下也能奏效 - 键可以在没有匹配实体的情况下存在。当然，尝试在数据存储查看器中跟随 link 到用户组失败：
Traceback (most recent call last):
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1536, in __call__
rv = self.handle_exception(request, response, e)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1530, in __call__
rv = self.router.dispatch(request, response)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1278, in default_dispatcher
return route.handler_adapter(request, response)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 1102, in __call__
return handler.dispatch()
File "/home/usr_local/google_appengine/google/appengine/tools/devappserver2/admin/admin_request_handler.py", line 96, in dispatch
super(AdminRequestHandler, self).dispatch()
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 572, in dispatch
return self.handle_exception(e, self.app.debug)
File "/home/usr_local/google_appengine_1.9.40/lib/webapp2-2.5.1/webapp2.py", line 570, in dispatch
return method(*args, **kwargs)
File "/home/usr_local/google_appengine/google/appengine/tools/devappserver2/admin/datastore_viewer.py", line 741, in get
entities = [datastore.Get(entity_key)]
File "/home/usr_local/google_appengine/google/appengine/api/datastore.py", line 671, in Get
return GetAsync(keys, **kwargs).get_result()
File "/home/usr_local/google_appengine/google/appengine/api/apiproxy_stub_map.py", line 613, in get_result
return self.__get_result_hook(self)
File "/home/usr_local/google_appengine/google/appengine/datastore/datastore_rpc.py", line 1717, in __get_hook
entities = extra_hook(entities)
File "/home/usr_local/google_appengine/google/appengine/api/datastore.py", line 640, in local_extra_hook
raise datastore_errors.EntityNotFoundError()
EntityNotFoundError
因此您可能想要显示创建实体的实际代码和完整的回溯，可能还有其他事情正在发生。
您的回溯表明问题不是创建实体，而是保存您的会话：
File "/var/www/mywebsite/public_html/lib/flask/app.py", line 926, in save_session
return self.session_interface.save_session(self, session, response)
您似乎在会话内容中包含了关键对象（可能是通过包含整个 User 实体？），这就是导致失败的原因。为此，需要序列化密钥，您可以为此使用 key.urlsafe()。有关示例，请参见此答案：
如果您确实在会话中包含了整个 User 实体，您可以只包含它的 urlsafe 密钥。
是的，这就是问题的根源：
session['group_key'] = user.group_key
改为：
session['group_key'] = user.group_key.urlsafe()
您将像这样检索它：
urlsafe_key = session.get('group_key')
if urlsafe_key:
group_key = ndb.Key(urlsafe=urlsafe_key)