Hello, I'm newbie here
I'm trying to write a little web app with neo4j 4.0 python 3.8 and flask.
I followed the doc here https://neo4j.com/docs/driver-manual/current/session-api/simple/#driver-simple-transaction-fn
when I execute my python code directly in the python shell I get the expected result
when I execute it from the web page I get the error **TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement.
**
My code is very simple :
def search_news_by_name(tx, name):
query = """
MATCH (n:News {Symbol: $name})
RETURN n.Date, n.Symbol, n.Title
ORDER BY n.Date DESC
LIMIT 25
"""
print(query, name, (tx.run(query, name=name)).__dict__)
newsList = []
for news in tx.run(query, name=name):
newsList.append({'Date': news['n.Date'],'Symbol': news['n.Symbol'],'Title': news['n.Title']})
return newsList
def search_query(name):
name='UBI'
driver = GraphDatabase.driver("neo4j://server.dscl.fr:7687", auth=("neo4j", "s56brApr"))
with driver.session() as session:
newsList = session.read_transaction(search_news_by_name, name)
driver.close()
return (newsList)
and from the Flask App :
@app.route('/search', methods = ['GET', 'POST'])
def search():
if request.method == 'POST':
my_data = search_query(request.form.get('search'))
The full debug trace gives :
* Debugger PIN: 339-966-619
query= MATCH (n:News {Symbol: $name})
RETURN n.Date, n.Symbol, n.Title
ORDER BY n.Date DESC
LIMIT 25
name= UBI
{'_connection': <neo4j.io._bolt4x0.Bolt4x0 object at 0x7fe008bab880>, '_hydrant': <neo4j.data.DataHydrator object at 0x7fe008baba60>, '_on_closed': <bound method Transaction._result_on_closed_handler of <neo4j.work.transaction.Transaction object at 0x7fe008bab850>>, '_metadata': {'query': '\n\t\tMATCH (n:News {Symbol: $name}) \n\t\tRETURN n.Date, n.Symbol, n.Title \n\t\tORDER BY n.Date DESC\n\t\tLIMIT 25\n\t\t', 'parameters': {'name': 'UBI'}, 'server': <neo4j.api.ServerInfo object at 0x7fe008baba00>, 't_first': 0, 'fields': ['n.Date', 'n.Symbol', 'n.Title'], 'qid': 0}, '_record_buffer': deque([]), '_summary': None, '_bookmark': None, '_qid': 0, '_fetch_size': 1000, '_discarding': False, '_attached': True, '_streaming': False, '_has_more': False, '_closed': False, '_keys': ['n.Date', 'n.Symbol', 'n.Title']}
92.154.43.222 - - [23/Jun/2020 09:16:31] "POST /search HTTP/1.1" 500 -
Traceback (most recent call last):
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 2464, in __call__
return self.wsgi_app(environ, start_response)
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 2450, in wsgi_app
response = self.handle_exception(e)
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 1867, in handle_exception
reraise(exc_type, exc_value, tb)
File "/usr/local/lib/python3.8/dist-packages/flask/_compat.py", line 39, in reraise
raise value
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 2447, in wsgi_app
response = self.full_dispatch_request()
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 1953, in full_dispatch_request
return self.finalize_request(rv)
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 1968, in finalize_request
response = self.make_response(rv)
File "/usr/local/lib/python3.8/dist-packages/flask/app.py", line 2097, in make_response
raise TypeError(
TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement.
Any help will be appreciated
