I keep getting this error local variable 'url' referenced before assignment

Question

It doesnt run the loop

Changed the variable url name and still didnt work

@

app.route("/processbuy", methods=["POST"])
def processbuy():
 if request.method == "POST":
        index2 = request.form['index2']
        querystring = {"api_key":"NN2T8jrqC6UH5inDezHh"}
        payload = ""
        headers = {
            'cache-control': "no-cache",
            'Postman-Token': "d2cd69a4-e6d4-466c-88b3-0a3987b1cd7d"
        }                              
        print("dsad")
        if index2 == "Stock Market Index at Exchange: NYSE":
                url = "https://www.quandl.com/api/v3/datasets/WFE/INDEXES_NYSE.json"
                response = requests.request("GET", url, data=payload, headers=headers, params=querystring)
                indiceData = json.loads(response.text)
                latestIndicePrices = indiceData["dataset"]["data"][0]
                indexValue = float(latestIndicePrices[5])

        else: 
                if index2 == "NASDAQ-100 Target 25 Notional Net Return Index(XNDXT25NNR)":
                    url = "https://www.quandl.com/api/v3/datasets/NASDAQOMX/XNDXT25NNR.json"
                elif index2 == "Stock Market Index at Exchange: London Stock Exchange FTSE 100":
                    url = "https://www.quandl.com/api/v3/datasets/WFE/INDEXES_LONDONSEFTSE.json"
                elif index2 == "Stock Market Index at Exchange: NYSE":
                    url = "https://www.quandl.com/api/v3/datasets/WFE/INDEXES_NYSE.json"
                response = requests.request("GET", url, data=payload, headers=headers, params=querystring)
                print("response="+response.text)
                indiceData = json.loads(response.text)
                latestIndicePrices = indiceData["dataset"]["data"][0]
                indexValue = float(latestIndicePrices[1])
        print("dwwsw")
        token = session['oauth_token']
        customersAccount = session['fidor_customer']
        customerDetails = customersAccount['data'][0]

When added a print after the loop it suppose to show the print but it didnt for me.

Answer 1

只有将index2定义为某变量时，才会初始化变量url

Answer 2

Your problem is the variable url might never be assigned any value. The reason for that is your if conditions.

if condition1:
    url = "something"
else:
    if condition2:
        url = "something"
    elif condition3:
        url = "something"
    elif condition4:
        url = "something"
    else: # hypothetical
        url is undefined here # and here is your issue

You can solve this by adding that last else catch or by initializing url to a default value before you check for any condition.

If you use a good IDE like Pycharm it would give you warning about these issues even before you run the code.