db.py

from .tesco_api import TescoRequestClient
from .models import TescoProduct

def insert_basket():
  # create Tesco Request Client
  client = TescoRequestClient(email, password, dev_app, app_key)
  products = client.format() # See note in tesco_api.py about this function name
  
  for product in products:
    # insert product into database
    product_id = product.pop('product_id')
    obj, created = TescoProduct.objects.get_or_create(product_id=product_id, defaults=product)
    
    if created:
      print("New product created")
  
    

tesco_api.py

class TescoRequestClient:

    # __init__ is used to create TescoRequestClient object. Request client is an object that allows us to make
    # requests to tesco it should not hold any product info
    def __init__(self, email, password, dev_key, app_key):
        self.session_key = self.login(email, password, dev_key, app_key)
        self.basket_items_ids = self.get_basket() # Don't store the basket here
        self.all_product_data = self.format() # Don't store the products here
        
    def req(self, params):
        r = requests.get("https://secure.techfortesco.com/tescolabsapi/restservice.aspx", params=params)
        r = r.json() if r.status_code == 200 else "fail"
        return dict(r)

    def login(self, email, password, dev_key, app_key):
        params = {
            "Command": "LOGIN",
            "Email": email,
            "Password": password,
            "Developerkey": dev_key,
            "Applicationkey": app_key,
        }
        login_details = self.req(params)
        return login_details['SessionKey']

    def search(self, search_text, extended):
        params = {
            "Command": "PRODUCTSEARCH",
            "SearchText": search_text,
            "SessionKey": self.session_key,
            "ExtendedInfo": "Y" if extended else "N"
        }
        r = self.req(params)
        return r

    def get_basket(self):
        basket_items_ids = list()
        params = {
            "Command": "LISTBASKET",
            "SessionKey": self.session_key
        }
        for item in self.req(params)['BasketLines']:
            basket_items_ids.append(int(item['ProductId'].strip("u")))

        return basket_items_ids
    
    def edit_basket(self, product_id, q):
        while not(re.search('-[0-9]*|[0-9]', str(q))):
            q = input("Please select quantity (pos int for add, neg int for rm)")
        params = {
            "Command": "CHANGEBASKET",
            "SessionKey": self.session_key,
            "ChangeQuantity": int(q),
            "ProductId": product_id,
        }
        r = self.req(params)
        return r['StatusInfo']
    
    def extract(self, place, regex='(?<=.)*[0-9]+(?=([ ]|)[gG])(?=.)*'):
        obj = re.search(regex, place)
        return float(obj.group(0)) if obj and obj.group(0).isdigit() else (obj.group() if obj else "False")
    
    # Change the name of the this function format is a built in function (check the IDE for this error)
    def format(self):
        biids = self.basket_items_ids
        product_data = list()
        for x in biids:
            print x
            info = {"energy": 0, "fat": 0, "saturates": 0, "carbohydrate": 0, "sugar": 0, "protein": 0, "fibre": 0}
            params = {
                "Command": "PRODUCTSEARCH",
                "SessionKey":  self.session_key,
                "SearchText": int(x),
                "ExtendedInfo": "Y",
            }
            p = self.req(params)['Products'][0]
            if "Nutrients" in p.keys():
                for nutrient in p['Nutrients']:
                    for kword in info:
                        nutri_name = re.search('(?<=.)*' + kword + r'(?=.)*', nutrient['NutrientName'], flags=re.IGNORECASE)
                        if nutri_name:
                            info[str(nutri_name.group(0).lower()).strip("u")] = float(re.search('[0-9]*((\.)[0-9]*|)', nutrient['SampleSize']).group(0))
                # info["portion_size"] = self.extract(p['Nutrients'][0]['ServingDescription'])
                # info["per_unit_weight"] = self.extract(p['Nutrients'][0]['SampleDescription'])
                # commented out as I now realise that these apply to a lot less products than I originally realised

            info["product_name"] = str(p['Name']).strip("u")
            info["product_id"] = int(str(p['ProductId']).strip("u"))
            info["peodprice"] = self.extract(str(p['Price']), '[0-9]*((\.)[0-9]*|)')

            product_data.append(info)

        return product_data

    def make_products(self):
        for product in self.all_product_data:  # all_product_data is the list of dictionaries with the product data
            print product
            # Product is a dictionary containing the data for one single product
            # I was hoping to be able to pass the dictionary of products into
            create_tesco_product(product)