Files
supermarket-scraping/supermarket_chain.py

125 lines
3.6 KiB
Python

from abc import abstractmethod
from argparse import ArgumentTypeError
from typing import Dict, List
import requests
from aenum import Enum
from bs4.element import Tag
from item import Item
class Meta(type):
def __repr__(cls):
return cls.__name__
class SupermarketChain(object, metaclass=Meta):
"""
A class representing a supermarket chain.
"""
class XMLFilesCategory(Enum):
"""
An enum class of different XML files produced by a supermarket chain
"""
All, Prices, PricesFull, Promos, PromosFull, Stores = range(6)
_promotion_tag_name = "Promotion"
_promotion_update_tag_name = "PromotionUpdateDate"
_date_format = "%Y-%m-%d"
_date_hour_format = "%Y-%m-%d %H:%M"
_update_date_format = "%Y-%m-%d %H:%M"
_item_tag_name = "Item"
@property
def promotion_tag_name(self):
return type(self)._promotion_tag_name
@property
def promotion_update_tag_name(self):
return type(self)._promotion_update_tag_name
@property
def date_format(self):
return type(self)._date_format
@property
def date_hour_format(self):
return type(self)._date_hour_format
@property
def update_date_format(self):
return type(self)._update_date_format
@property
def item_tag_name(self):
return type(self)._item_tag_name
@staticmethod
def is_valid_store_id(store_id: int) -> bool:
"""
This method returns whether a given store ID is valid (French Natural number).
:param store_id: A given store ID
"""
return isinstance(store_id, int) and store_id >= 0
@staticmethod
def store_id_type(store_id: str) -> str:
"""
This method used as a type verification for store_id.
:param store_id: A given store ID
:return: The given store_id if valid, else raise an ArgumentTypeError.
"""
if not SupermarketChain.is_valid_store_id(int(store_id)):
raise ArgumentTypeError(
f"Given store_id: {store_id} is not a valid store_id."
)
return store_id
@staticmethod
@abstractmethod
def get_download_url_or_path(
store_id: int, category: XMLFilesCategory, session: requests.Session
) -> str:
"""
This method scrapes the supermarket's website and according to the given store id and category,
it returns a url containing the data or or a path to a gz file containing the data.
:param store_id: A given ID of a store
:param category: A given category
:return: A downloadable link of the data for a given store and category
:param session: A given session object
"""
pass
@staticmethod
def get_items(promo: Tag, items_dict: Dict[str, Item]) -> List[Item]:
"""
This method returns a list of the items that participate in a given promotion.
:param promo: A given promotion
:param items_dict: A given dictionary of products
"""
items = list()
for item in promo.find_all("Item"):
item_code = item.find("ItemCode").text
full_item_info = items_dict.get(item_code)
if full_item_info:
items.append(full_item_info)
return items
@staticmethod
def get_null_items(promo: Tag, items_dict: Dict[str, Item]) -> List[str]:
"""
This function returns all the items in a given promotion which do not appear in the given items_dict.
"""
return [
item.find("ItemCode").text
for item in promo.find_all("Item")
if not items_dict.get(item.find("ItemCode").text)
]