Python passing arguments to function Flask - python-3.x

Question

I am writing a Flask application script and have encountered a function that accepts arguments and functions outside of the flask app in a standalone script but will not accept the the 'TFEVT_node_id'argument I pass to it inside of the Flask app. Here is the Flask code:
#################################################
# Flask Setup
#################################################
#app = Flask(__name__, static_url_path='')
app = Flask(__name__)
CORS(app)
#################################################
#global variables
TFEVT_node_id = ''
token = ''
#################################################
# CityIQ API calls
#################################################
def get_token():
print("Get Token")
url = 'https://auth.aa.cityiq.io/oauth/token'
querystring = {"grant_type":"client_credentials"}
response = requests.get(url, auth=HTTPBasicAuth(client,secret), params=querystring).json()
token = response['access_token']
print("Token Received")
return token
#given a specific subasset this function returns the CityIQ traffic events for a given period of time in minutes
def get_traffic(TFEVT_node_id, lookback_minutes):
url_string = '/events'
url = "https://sandiego.cityiq.io/api/v2/event/assets/"+TFEVT_node_id+url_string
ts = datetime.datetime.now().timestamp()
CityIQ_Current_TS = int(ts*1000)
CityIQ_TS_Calc_TS = datetime.datetime.now() - timedelta(minutes=lookback_minutes)
CityIQ_Starttime_TS = int((ts-(lookback_minutes*60))*1000)
querystring = {"eventType":"TFEVT","startTime":CityIQ_Starttime_TS,"endTime":CityIQ_Current_TS,"pageSize":"100"}
payload = ""
headers = {
'Authorization': "Bearer {}".format(token),
'Predix-Zone-Id': "SD-IE-TRAFFIC",
'cache-control': "no-cache",
}
response = requests.request("GET", url, headers=headers, params=querystring).json()
return(response)
#give it an CityIQ node ID and it will return the asset TFEVT child .
def get_asset_TFEVT(node_id):
url = "https://sandiego.cityiq.io/api/v2/metadata/assets/"+node_id+"/subAssets"
payload = ""
headers = {
'Authorization': "Bearer {}".format(token),
'Predix-Zone-Id': "SD-IE-ENVIRONMENTAL",
'cache-control': "no-cache",
}
response = requests.request("GET", url, data=payload, headers=headers).json()
for i in response['assets']:
if any('TFEVT' in i for i in [i][0]['eventTypes']):
global TFEVT_node_id
TFEVT_node_id = ([i][0]['assetUid'])
return(TFEVT_node_id)
#test def that should be removed in production
def test(TFEVT_node_id, lookback_minutes):
found_cars = get_traffic(TFEVT_node_id, lookback_minutes)
print(found_cars)
return(found_cars)
#################################################
# Flask Routes
#################################################
#app.route('/')
def hello_world():
global token
token = get_token()
return 'documentation comming soon!'
#app.route('/test/<string:node_id>')
def go(node_id):
global token
token = get_token()
global TFEVT_node_id
TFEVT_node_id = get_asset_TFEVT(node_id)
cars_list = []
lookback_minutes = 15
env_output = {}
ccars = test(TFEVT_node_id, lookback_minutes)
cars_list.append(ccars)
env_output.update({'Cars' : cars_list})
if __name__ == '__main__':
app.run()
Again, I am getting the desired result when these functions are run outside of a Flask app. Inside of the Flask app (running the code above) returns a TypeError: The view function did not return a valid response. I have traced that back to the 404 response in the gettraffic function where the lookback minutes variable is getting through but the TFEVT_node_id isn't.
I am new to Python.

Answer 1

Your go() function does not have a return. A response is expected. See: About responses.