我得到错误期望值:第1行第1列(字符0)时试图解码JSON。

我用于API调用的URL在浏览器中工作正常,但在通过curl请求完成时给出了这个错误。下面是我用于curl请求的代码。

错误发生在返回simplejson.loads(response_json)时

response_json = self.web_fetch(url)
response_json = response_json.decode('utf-8')
return json.loads(response_json)


def web_fetch(self, url):
    buffer = StringIO()
    curl = pycurl.Curl()
    curl.setopt(curl.URL, url)
    curl.setopt(curl.TIMEOUT, self.timeout)
    curl.setopt(curl.WRITEFUNCTION, buffer.write)
    curl.perform()
    curl.close()
    response = buffer.getvalue().strip()
    return response

回溯:

File "/Users/nab/Desktop/myenv2/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  111.                         response = callback(request, *callback_args, **callback_kwargs)
File "/Users/nab/Desktop/pricestore/pricemodels/views.py" in view_category
  620.     apicall=api.API().search_parts(category_id= str(categoryofpart.api_id), manufacturer = manufacturer, filter = filters, start=(catpage-1)*20, limit=20, sort_by='[["mpn","asc"]]')
File "/Users/nab/Desktop/pricestore/pricemodels/api.py" in search_parts
  176.         return simplejson.loads(response_json)
File "/Users/nab/Desktop/myenv2/lib/python2.7/site-packages/simplejson/__init__.py" in loads
  455.         return _default_decoder.decode(s)
File "/Users/nab/Desktop/myenv2/lib/python2.7/site-packages/simplejson/decoder.py" in decode
  374.         obj, end = self.raw_decode(s)
File "/Users/nab/Desktop/myenv2/lib/python2.7/site-packages/simplejson/decoder.py" in raw_decode
  393.         return self.scan_once(s, idx=_w(s, idx).end())

Exception Type: JSONDecodeError at /pricemodels/2/dir/
Exception Value: Expecting value: line 1 column 1 (char 0)

当前回答

我做了:

打开test.txt文件,写入数据 打开test.txt文件,读取数据

所以我没有在1点后关闭文件。

我添加了

outfile.close()

现在起作用了

其他回答

很多时候,这是因为你试图解析的字符串是空的:

>>> import json
>>> x = json.loads("")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/__init__.py", line 348, in loads
    return _default_decoder.decode(s)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/decoder.py", line 337, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/decoder.py", line 355, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

你可以通过事先检查json_string是否为空来补救:

import json

if json_string:
    x = json.loads(json_string)
else:
    # Your code/logic here 
    x = {}

对我来说,这是服务器响应的东西,而不是200,响应不是json格式的。我最终在json解析之前这样做:

# this is the https request for data in json format
response_json = requests.get() 

# only proceed if I have a 200 response which is saved in status_code
if (response_json.status_code == 200):  
     response = response_json.json() #converting from json to dictionary using json library

如果您是Windows用户,Tweepy API可以在数据对象之间生成空行。由于这种情况,您可能会得到“JSONDecodeError: expected value: line 1 column 1 (char 0)”错误。要避免此错误,可以删除空行。

例如:

 def on_data(self, data):
        try:
            with open('sentiment.json', 'a', newline='\n') as f:
                f.write(data)
                return True
        except BaseException as e:
            print("Error on_data: %s" % str(e))
        return True

参考: Twitter流API从None给出JSONDecodeError(“期望值”,s, err.value)

我在请求(python库)方面也遇到了同样的问题。它恰好是接受编码头。

它是这样设置的:'accept-encoding': 'gzip, deflate, br'

我只是从请求中删除它,并停止得到错误。

在请求库中,当你遇到404这样的http错误代码并试图将响应解析为JSON时,JSONDecodeError就会发生!

您必须首先检查200 (OK)或让它在错误时抛出以避免这种情况。 我希望它失败时没有那么神秘的错误信息。

注意:正如Martijn Pieters在评论中所说,服务器可以在出现错误时使用JSON进行响应(这取决于实现),因此检查Content-Type报头更可靠。