我正在创建一个使用了用flask + python编写的服务器的ios应用程序，当我与服务器建立连接以注册用户时，我不断得到一个＆＃39; NoneType＆＃39;对象不是我的server.py文件中的可订阅错误。基本上我的问题是导致此错误的原因以及我如何解决此问题。此外，如果有人能指出我在不同或更简单的方式做正确的方向，我将不胜感激谢谢！
这是server.py文件：
import bcrypt
from flask import Flask, request, make_response,jsonify
from flask_restful import Resource, Api
from pymongo import MongoClient
from json import JSONEncoder
from bson.objectid import ObjectId
from functools import wraps
app = Flask(__name__)
mongo = MongoClient('localhost', 27017)
app.db = mongo.eventure_db
app.bcrypt_rounds = 12
api = Api(app)
# Authentication code.
def check_auth(username, password):
# check_auth should access the database and check if the username + password are correct.
# create a collection to hold the users.
user_collection = app.db.users
user = user_collection.find_one({'username': username})
if user is None:
return False
else:
# check if hash generated matches stored hash
encodedPassword = password.encode('utf-8')
if bcrypt.hashpw(encodedPassword, user['password']) == user['password']:
return True
else:
return False
# User resource
class User(Resource):
def post(self):
if (request.json['username'] == None
or request.json['password'] == None):
return ({'error': 'Request requires username and password'},
400,
None)
user_collection = app.db.users
user = user_collection.find_one({'username': request.json['username']})
if user is not None:
return ({'error': 'Username already in use'}, 400, None)
else:
encodedPassword = request.json['password'].encode('utf-8')
hashed = bcrypt.hashpw(
encodedPassword, bcrypt.gensalt(app.bcrypt_rounds))
request.json['password'] = hashed
user_collection.insert_one(request.json)
@requires_auth
def get(self):
return (None, 200, None)
api.add_resource(User, '/eventure/api/v1.1/user/')
# Must define a custom JSON Serializer for flask_restful
# this is because ObjectId is not a string, and therefore,
# Flask's default serializer cannot serialize it.
@api.representation('application/json')
def output_json(data, code, headers=None):
resp = make_response(JSONEncoder().encode(data), code)
resp.headers.extend(headers or {})
return resp
if __name__ == '__main__':
app.config['TRAP_BAD_REQUEST_ERRORS'] = True
app.run(host='localhost', port=8789, debug=True)
这是我在swift中的注册函数：
@IBAction func register(_ sender: AnyObject) {
let url = URL(string: "http://localhost:8789/eventure/api/v1.1/user/")
var request = URLRequest(url: url!)
request.httpMethod = "POST"
request.setValue(generateBasicAuthHeader(username: username.text!, password: password.text!), forHTTPHeaderField: "Authorization")
let session = URLSession.shared
let task = session.dataTask(with: request) { data, response, error in
if let response = response, let data = data {
print(String(data: data, encoding: String.Encoding.utf8))
}
}
task.resume()
self.username.text = ""
self.password.text = ""
}
回溯：
[28/Oct/2016 19:22:33] "POST /eventure/api/v1.1/user/ HTTP/1.1" 500 -
Traceback (most recent call last):
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1836, in __call__
return self.wsgi_app(environ, start_response)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1820, in wsgi_app
response = self.make_response(self.handle_exception(e))
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask_restful/__init__.py", line 270, in error_router
return original_handler(e)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1403, in handle_exception
reraise(exc_type, exc_value, tb)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/_compat.py", line 32, in reraise
raise value.with_traceback(tb)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1817, in wsgi_app
response = self.full_dispatch_request()
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1477, in full_dispatch_request
rv = self.handle_user_exception(e)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask_restful/__init__.py", line 270, in error_router
return original_handler(e)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1381, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/_compat.py", line 32, in reraise
raise value.with_traceback(tb)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1475, in full_dispatch_request
rv = self.dispatch_request()
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/app.py", line 1461, in dispatch_request
return self.view_functions[rule.endpoint](**req.view_args)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask_restful/__init__.py", line 471, in wrapper
resp = resource(*args, **kwargs)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask/views.py", line 84, in view
return self.dispatch_request(*args, **kwargs)
File "/Users/Dynee/eventure-backend-api/development/lib/python3.5/site-packages/flask_restful/__init__.py", line 581, in dispatch_request
resp = meth(*args, **kwargs)
File "/Users/Dynee/eventure-backend-api/server.py", line 128, in post
if (request.json['username'] == None
TypeError: 'NoneType' object is not subscriptable
此处还有generateBasicAuthHeader函数：
func generateBasicAuthHeader(username: String, password: String) -> String {
let loginString = String(format: "%@:%@", username, password)
let loginData = loginString.data(using: String.Encoding.utf8)!
let base64LoginString = loginData.base64EncodedString()
let basicAuthHeader = "Basic \(base64LoginString)"
return basicAuthHeader
}
答案 0 :(得分：13)
您需要为content-type明确设置application/json到request.json才能在烧瓶中正常工作。如果未设置标头，request.json将返回无。
但建议从帖子请求中获取烧瓶中的json数据是使用request.get_json()
我还建议您在使用ios申请前使用漂亮的requests模块测试您的API。
>>> import requests
>>> requests.post(url, json={'name': 'hello world'})
它已设置了发出json请求所需的相应标头
如果它适用于requests模块，那么您可以确定它可以与您的ios应用程序一起使用。您只需要确保设置正确的content-type。
您可以强制告诉flask忽略{/ 1}}标题
content-type