json.decoder.JSONDecodeHeroku Flask应用程序中的错误-如何调试

Question

我已经构建了一个heroku flask应用程序，该应用程序连接到用于Dynamics365的web API。我的应用程序不时崩溃，并出现以下错误(从Heroku日志粘贴的副本(：

2021-03-09T12:08:51.463416+00:00 heroku[router]: at=info method=GET path="/" host=holmed.herokuapp.com request_id=16a135a9-7b41-4813-944d-f616551b4875 fwd="89.64.66.42" dyno=web.1 connect=1ms service=156ms status=500 bytes=385 protocol=https
2021-03-09T12:08:51.461297+00:00 app[web.1]: [2021-03-09 12:08:51,460] ERROR in app: Exception on / [GET]
2021-03-09T12:08:51.461320+00:00 app[web.1]: Traceback (most recent call last):
2021-03-09T12:08:51.461321+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 2447, in wsgi_app
2021-03-09T12:08:51.461322+00:00 app[web.1]:     response = self.full_dispatch_request()
2021-03-09T12:08:51.461323+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1952, in full_dispatch_request
2021-03-09T12:08:51.461324+00:00 app[web.1]:     rv = self.handle_user_exception(e)
2021-03-09T12:08:51.461324+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1821, in handle_user_exception
2021-03-09T12:08:51.461324+00:00 app[web.1]:     reraise(exc_type, exc_value, tb)
2021-03-09T12:08:51.461325+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/_compat.py", line 39, in reraise
2021-03-09T12:08:51.461326+00:00 app[web.1]:     raise value
2021-03-09T12:08:51.461326+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1950, in full_dispatch_request
2021-03-09T12:08:51.461327+00:00 app[web.1]:     rv = self.dispatch_request()
2021-03-09T12:08:51.461327+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/flask/app.py", line 1936, in dispatch_request
2021-03-09T12:08:51.461327+00:00 app[web.1]:     return self.view_functions[rule.endpoint](**req.view_args)
2021-03-09T12:08:51.461328+00:00 app[web.1]:   File "/app/app.py", line 222, in index
2021-03-09T12:08:51.461328+00:00 app[web.1]:     qualif = qualifications()[1]
2021-03-09T12:08:51.461329+00:00 app[web.1]:   File "/app/query.py", line 877, in qualifications
2021-03-09T12:08:51.461329+00:00 app[web.1]:     df = json_normalize(crmres.json()["value"])
2021-03-09T12:08:51.461330+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/site-packages/requests/models.py", line 898, in json
2021-03-09T12:08:51.461330+00:00 app[web.1]:     return complexjson.loads(self.text, **kwargs)
2021-03-09T12:08:51.461331+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/json/__init__.py", line 354, in loads
2021-03-09T12:08:51.461332+00:00 app[web.1]:     return _default_decoder.decode(s)
2021-03-09T12:08:51.461332+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/json/decoder.py", line 339, in decode
2021-03-09T12:08:51.461332+00:00 app[web.1]:     obj, end = self.raw_decode(s, idx=_w(s, 0).end())
2021-03-09T12:08:51.461333+00:00 app[web.1]:   File "/app/.heroku/python/lib/python3.6/json/decoder.py", line 357, in raw_decode
2021-03-09T12:08:51.461333+00:00 app[web.1]:     raise JSONDecodeError("Expecting value", s, err.value) from None
2021-03-09T12:08:51.461340+00:00 app[web.1]: json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)
2021-03-09T12:08:51.462396+00:00 app[web.1]: 10.12.107.73 - - [09/Mar/2021:12:08:51 +0000] "GET / HTTP/1.1" 500 205 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.190 Safari/537.36"

这是我处理与API 通信的代码

tokentype, token = get_access_token()
bearer = f'{tokentype} {token}'
DATA_URL = f"https://holmed.crm4.dynamics.com/data/"
crm_web_api = 'https://holmed.api.crm4.dynamics.com/api/data/v9.1'  # full path to web api endpoint
crm_request_headers = {
'Authorization': bearer,
'OData-MaxVersion': '4.0',
'OData-Version': '4.0',
'Accept': 'application/json',
'Content-Type': 'application/json; charset=utf-8',
'Prefer': 'odata.maxpagesize=500',
'Prefer': 'odata.include-annotations=OData.Community.Display.V1.FormattedValue'
}
def crm_read(query_string):
return requests.get(crm_web_api + query_string, headers=crm_request_headers)
def qualifications():
query_string = "/is_potentialpatients?$filter=statuscode%20eq%20100000001"
crmres = crm_read(query_string)
df = json_normalize(crmres.json()["value"]) # THE ERROR HAPPENS OVER HERE
if df.empty:
html = "Brak oczekujących na kwalifikacje."
qualif = 0
else:
try:
df = df[['is_name', 'is_phonenumber', 'is_comments', '[e-mail]',
'is_referral_date']]
df = df.rename(columns={'is_name': 'Nazwisko', 'is_phonenumber': 'Numer telefonu', 'is_comments': 'Uwagi',
'[e-mail]': 'Szpital kierujący',
'is_referral_date': 'Data ze skierowania'})
except KeyError:
df = df[['is_name', 'is_phonenumber', 'is_comments',
'is_referral_date']]
df = df.rename(columns={'is_name': 'Nazwisko', 'is_phonenumber': 'Numer telefonu', 'is_comments': 'Uwagi','is_referral_date': 'Data ze skierowania'})
df['Data ze skierowania'] = df['Data ze skierowania'].str.slice(start=0, stop=10)
qualif = df['Nazwisko'].count()
df = df.fillna("")
html = df.to_html()
html = html.replace("dataframe", "table table-hover table-sm")
html = html.replace("None", "")
return html, qualif
qualif = qualifications()[1]
print(qualif)

我用于API调用的URL在浏览器中运行良好。当我从IDE执行python代码时，它运行得很好。当我在Heroku上重新构建我的应用程序时，它又开始工作了，但几天后出现了上述错误。

我已经复习了所有关于堆栈溢出的相关问题，但没有一个特别涉及heroku，我找不到任何解决问题的方法。

有什么想法吗？

编辑：我被要求"调试细节"；。我试图通过在IDE中运行上面的代码来重现这个错误。但是，代码运行良好。因此，我不确定我能进一步提供什么调试细节。。。你将如何调试它？：-(

Answer 1

为了调试问题，您需要改进应用程序日志记录。我会做以下更改来调试问题：

def crm_read(query_string):
print(crm_web_api + query_string)
response = requests.get(crm_web_api + query_string, headers=crm_request_headers)
print(response.status_code)
return response
def qualifications():
query_string = "/is_potentialpatients?$filter=statuscode%20eq%20100000001"
crmres = crm_read(query_string)
print(crmres.json())
df = json_normalize(crmres.json()["value"]) # THE ERROR HAPPENS OVER HERE

如果您正在使用Flask，只需将print语句替换为app.logger.info，并相应地降低应用程序日志记录级别。这应该可以让你在生产中调试你的应用程序正在发生的事情。