从AJAX POST获取JSON数据的问题(Issues with getting JSON data from AJAX POST)

 AJAX调用如下所示： 
 
        json_dictionary = {url : url, profile_dict: dictionary, final_dict : final_dictionary}
        $.ajax({
            url: "https://localhost:8090/add_profile_data",
            type: "POST",
            data: JSON.stringify(json_dictionary),
            contentType:'application/json',
            success:function() {
                console.log('added profile data')
            }
        })
 
 客户端看起来像这样： 
 
@app.route('/add_profile_data', methods=['POST', 'GET', 'OPTIONS'])
def add():
    data = request.json
    print(type(data))
 
 这是有效的，打印的结果是<type 'dict'> 
 
 此外，当我打印data对象时，一切都在那里。 
 
 但是，当我尝试： 
 
@app.route('/add_profile_data', methods=['POST', 'GET', 'OPTIONS'])
def add():
    data = request.json
    print(data.keys())
 
 我收到一个错误： AttributeError: 'NoneType' object has no attribute 'keys' 
 
 我不明白为什么会这样？ 有什么想法吗？ 
 
 更新： 
 
 将服务器更改为此，现在看到NoneType用于print(type(data))服务器： 
 
@app.route('/add_profile_data', methods=['POST', 'GET', 'OPTIONS'])
def add():
    data = request.json
    print(type(data))
    print(data.keys())
 
 响应： 
 
<type 'NoneType'>
127.0.0.1 - - [04/Jan/2017 09:13:47] "OPTIONS /add_profile_data HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/flask/app.py", line 2000, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1991, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/Library/Python/2.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1567, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1988, in wsgi_app
    response = self.full_dispatch_request()
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1641, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Library/Python/2.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1544, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1639, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1625, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/morganallen/Dropbox/Coding_Projects/Prediction_Server/prediction_v2.py", line 172, in add
    print(data.keys())
AttributeError: 'NoneType' object has no attribute 'keys'
 
 我看到NoneType原因是NoneType ？ 

The AJAX call looks like this:
 
        json_dictionary = {url : url, profile_dict: dictionary, final_dict : final_dictionary}
        $.ajax({
            url: "https://localhost:8090/add_profile_data",
            type: "POST",
            data: JSON.stringify(json_dictionary),
            contentType:'application/json',
            success:function() {
                console.log('added profile data')
            }
        })
 
The client side looks like this:
 
@app.route('/add_profile_data', methods=['POST', 'GET', 'OPTIONS'])
def add():
    data = request.json
    print(type(data))
 
That works, and the result from print is <type 'dict'>
 
Also, when I print the data object, everything is there. 
 
However, when I try:
 
@app.route('/add_profile_data', methods=['POST', 'GET', 'OPTIONS'])
def add():
    data = request.json
    print(data.keys())
 
I get an error: AttributeError: 'NoneType' object has no attribute 'keys'
 
I don't understand why this is happening? Any thoughts? 
 
Update:
 
Changed the server to this, and now seeing NoneType for print(type(data)) Server:
 
@app.route('/add_profile_data', methods=['POST', 'GET', 'OPTIONS'])
def add():
    data = request.json
    print(type(data))
    print(data.keys())
 
Response:
 
<type 'NoneType'>
127.0.0.1 - - [04/Jan/2017 09:13:47] "OPTIONS /add_profile_data HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/Library/Python/2.7/site-packages/flask/app.py", line 2000, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1991, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/Library/Python/2.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1567, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1988, in wsgi_app
    response = self.full_dispatch_request()
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1641, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Library/Python/2.7/site-packages/flask_cors/extension.py", line 161, in wrapped_function
    return cors_after_request(app.make_response(f(*args, **kwargs)))
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1544, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1639, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Library/Python/2.7/site-packages/flask/app.py", line 1625, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/Users/morganallen/Dropbox/Coding_Projects/Prediction_Server/prediction_v2.py", line 172, in add
    print(data.keys())
AttributeError: 'NoneType' object has no attribute 'keys'
 
Any reason why I am seeing NoneType?

原文：https://stackoverflow.com/questions/41465778