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11 changed files with 393 additions and 11 deletions

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@ -82,6 +82,25 @@ pricesRouter.get('/bestDeals/:amount', async (req: Request, res: Response) => {
}
});
// GET prices/byProduct/list/[]
pricesRouter.get('/byProduct/list/:ids', async (req: Request, res: Response) => {
const productIds: [number] = JSON.parse(req.params.ids);
if (!productIds) {
res.status(400).send('Missing parameters.');
return;
}
try {
const prices: Prices = await PriceService.findListByProducts(productIds);
res.status(200).send(prices);
} catch (e) {
res.status(404).send(e.message);
}
});
// POST items/
// pricesRouter.post('/', async (req: Request, res: Response) => {

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@ -195,7 +195,6 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
let allPrices: Record<number, Price[]> = {};
// Get newest prices for every product at every vendor
const rows = await conn.query(
'WITH summary AS (\n' +
' SELECT p.product_id,\n' +
@ -222,10 +221,11 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
}
// Iterate over all prices to find the products with the biggest difference between amazon and other vendor
let deals = [];
for (let productId in Object.keys(allPrices)) {
if (allPrices[productId]) {
let pricesForProd = allPrices[productId];
let deals: Price[] = [];
Object.keys(allPrices).forEach(productId => {
if (allPrices[parseInt(productId)]) {
let pricesForProd = allPrices[parseInt(productId)];
// Get amazon price and lowest price from other vendor
let amazonPrice = {} as Price;
@ -234,6 +234,7 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
if (price.vendor_id === 1) {
amazonPrice = price;
} else {
// If there is no lowest price yet or the price of the current iteration is lower, set / replace it
if (!lowestPrice.price_in_cents || lowestPrice.price_in_cents > price.price_in_cents) {
lowestPrice = price;
}
@ -245,25 +246,25 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
'product_id': lowestPrice.product_id,
'vendor_id': lowestPrice.vendor_id,
'price_in_cents': lowestPrice.price_in_cents,
'timestamp' :lowestPrice.timestamp,
'timestamp': lowestPrice.timestamp,
'amazonDifference': (amazonPrice.price_in_cents - lowestPrice.price_in_cents),
'amazonDifferencePercent': ((1 - (lowestPrice.price_in_cents / amazonPrice.price_in_cents)) * 100),
};
// Push only deals were the amazon price is actually higher
if(deal.amazonDifferencePercent > 0) {
deals.push(deal);
if (deal.amazonDifferencePercent > 0) {
deals.push(deal as Price);
}
}
}
});
// Sort to have the best deals on the top
deals.sort((a, b) => a.amazonDifferencePercent < b.amazonDifferencePercent ? 1 : -1);
deals.sort((a, b) => a.amazonDifferencePercent! < b.amazonDifferencePercent! ? 1 : -1);
// Return only as many records as requested or the maximum amount of found deals, whatever is less
let maxAmt = Math.min(amount, deals.length);
for (let dealIndex = 0; dealIndex < maxAmt; dealIndex++){
for (let dealIndex = 0; dealIndex < maxAmt; dealIndex++) {
//console.log(deals[dealIndex]);
priceRows.push(deals[dealIndex] as Price);
}
@ -280,6 +281,70 @@ export const getBestDeals = async (amount: number): Promise<Prices> => {
return priceRows;
};
/**
* Get the lowest, latest, non-amazon price for each given product
* @param ids the ids of the products
*/
export const findListByProducts = async (productIds: [number]): Promise<Prices> => {
let conn;
let priceRows: Price[] = [];
try {
conn = await pool.getConnection();
let allPrices: Record<number, Price[]> = {};
// Get newest prices for every given product at every vendor
const rows = await conn.query(
'WITH summary AS (\n' +
' SELECT p.product_id,\n' +
' p.vendor_id,\n' +
' p.price_in_cents,\n' +
' p.timestamp,\n' +
' ROW_NUMBER() OVER(\n' +
' PARTITION BY p.product_id, p.vendor_id\n' +
' ORDER BY p.timestamp DESC) AS rk\n' +
' FROM prices p' +
' WHERE p.product_id IN (?)' +
' AND p.vendor_id != 1)\n' +
'SELECT s.*\n' +
'FROM summary s\n' +
'WHERE s.rk = 1', [productIds]);
// Write returned values to allPrices map with product id as key and a list of prices as value
for (let row in rows) {
if (row !== 'meta') {
if (!allPrices[parseInt(rows[row].product_id)]) {
allPrices[parseInt(rows[row].product_id)] = [];
}
allPrices[parseInt(rows[row].product_id)].push(rows[row]);
}
}
// Iterate over all products to find lowest price
Object.keys(allPrices).forEach(productId => {
if (allPrices[parseInt(productId)]) {
let pricesForProd = allPrices[parseInt(productId)];
// Sort ascending by price so index 0 has the lowest price
pricesForProd.sort((a, b) => a.price_in_cents > b.price_in_cents ? 1 : -1);
// Push the lowest price to the return list
priceRows.push(pricesForProd[0]);
}
});
} catch (err) {
throw err;
} finally {
if (conn) {
conn.end();
}
}
return priceRows;
};
// export const create = async (newItem: Product): Promise<void> => {
// let conn;
// try {

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12
Crawler/crawler/items.py Normal file
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@ -0,0 +1,12 @@
# Define here the models for your scraped items
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/items.html
import scrapy
class CrawlerItem(scrapy.Item):
# define the fields for your item here like:
# name = scrapy.Field()
pass

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@ -0,0 +1,103 @@
# Define here the models for your spider middleware
#
# See documentation in:
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
from scrapy import signals
# useful for handling different item types with a single interface
from itemadapter import is_item, ItemAdapter
class CrawlerSpiderMiddleware:
# Not all methods need to be defined. If a method is not defined,
# scrapy acts as if the spider middleware does not modify the
# passed objects.
@classmethod
def from_crawler(cls, crawler):
# This method is used by Scrapy to create your spiders.
s = cls()
crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
return s
def process_spider_input(self, response, spider):
# Called for each response that goes through the spider
# middleware and into the spider.
# Should return None or raise an exception.
return None
def process_spider_output(self, response, result, spider):
# Called with the results returned from the Spider, after
# it has processed the response.
# Must return an iterable of Request, or item objects.
for i in result:
yield i
def process_spider_exception(self, response, exception, spider):
# Called when a spider or process_spider_input() method
# (from other spider middleware) raises an exception.
# Should return either None or an iterable of Request or item objects.
pass
def process_start_requests(self, start_requests, spider):
# Called with the start requests of the spider, and works
# similarly to the process_spider_output() method, except
# that it doesnt have a response associated.
# Must return only requests (not items).
for r in start_requests:
yield r
def spider_opened(self, spider):
spider.logger.info('Spider opened: %s' % spider.name)
class CrawlerDownloaderMiddleware:
# Not all methods need to be defined. If a method is not defined,
# scrapy acts as if the downloader middleware does not modify the
# passed objects.
@classmethod
def from_crawler(cls, crawler):
# This method is used by Scrapy to create your spiders.
s = cls()
crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
return s
def process_request(self, request, spider):
# Called for each request that goes through the downloader
# middleware.
# Must either:
# - return None: continue processing this request
# - or return a Response object
# - or return a Request object
# - or raise IgnoreRequest: process_exception() methods of
# installed downloader middleware will be called
return None
def process_response(self, request, response, spider):
# Called with the response returned from the downloader.
# Must either;
# - return a Response object
# - return a Request object
# - or raise IgnoreRequest
return response
def process_exception(self, request, exception, spider):
# Called when a download handler or a process_request()
# (from other downloader middleware) raises an exception.
# Must either:
# - return None: continue processing this exception
# - return a Response object: stops process_exception() chain
# - return a Request object: stops process_exception() chain
pass
def spider_opened(self, spider):
spider.logger.info('Spider opened: %s' % spider.name)

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@ -0,0 +1,13 @@
# Define your item pipelines here
#
# Don't forget to add your pipeline to the ITEM_PIPELINES setting
# See: https://docs.scrapy.org/en/latest/topics/item-pipeline.html
# useful for handling different item types with a single interface
from itemadapter import ItemAdapter
class CrawlerPipeline:
def process_item(self, item, spider):
return item

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@ -0,0 +1,88 @@
# Scrapy settings for crawler project
#
# For simplicity, this file contains only settings considered important or
# commonly used. You can find more settings consulting the documentation:
#
# https://docs.scrapy.org/en/latest/topics/settings.html
# https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
BOT_NAME = 'crawler'
SPIDER_MODULES = ['crawler.spiders']
NEWSPIDER_MODULE = 'crawler.spiders'
# Crawl responsibly by identifying yourself (and your website) on the user-agent
USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36'
# Obey robots.txt rules
ROBOTSTXT_OBEY = False
# Configure maximum concurrent requests performed by Scrapy (default: 16)
#CONCURRENT_REQUESTS = 32
# Configure a delay for requests for the same website (default: 0)
# See https://docs.scrapy.org/en/latest/topics/settings.html#download-delay
# See also autothrottle settings and docs
DOWNLOAD_DELAY = 3
# The download delay setting will honor only one of:
#CONCURRENT_REQUESTS_PER_DOMAIN = 16
CONCURRENT_REQUESTS_PER_IP = 1
# Disable cookies (enabled by default)
COOKIES_ENABLED = False
# Disable Telnet Console (enabled by default)
#TELNETCONSOLE_ENABLED = False
# Override the default request headers:
#DEFAULT_REQUEST_HEADERS = {
# 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
# 'Accept-Language': 'en',
#}
# Enable or disable spider middlewares
# See https://docs.scrapy.org/en/latest/topics/spider-middleware.html
#SPIDER_MIDDLEWARES = {
# 'crawler.middlewares.CrawlerSpiderMiddleware': 543,
#}
# Enable or disable downloader middlewares
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html
#DOWNLOADER_MIDDLEWARES = {
# 'crawler.middlewares.CrawlerDownloaderMiddleware': 543,
#}
# Enable or disable extensions
# See https://docs.scrapy.org/en/latest/topics/extensions.html
#EXTENSIONS = {
# 'scrapy.extensions.telnet.TelnetConsole': None,
#}
# Configure item pipelines
# See https://docs.scrapy.org/en/latest/topics/item-pipeline.html
#ITEM_PIPELINES = {
# 'crawler.pipelines.CrawlerPipeline': 300,
#}
# Enable and configure the AutoThrottle extension (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/autothrottle.html
AUTOTHROTTLE_ENABLED = True
# The initial download delay
AUTOTHROTTLE_START_DELAY = 5
# The maximum download delay to be set in case of high latencies
#AUTOTHROTTLE_MAX_DELAY = 60
# The average number of requests Scrapy should be sending in parallel to
# each remote server
#AUTOTHROTTLE_TARGET_CONCURRENCY = 1.0
# Enable showing throttling stats for every response received:
#AUTOTHROTTLE_DEBUG = False
# Enable and configure HTTP caching (disabled by default)
# See https://docs.scrapy.org/en/latest/topics/downloader-middleware.html#httpcache-middleware-settings
#HTTPCACHE_ENABLED = True
#HTTPCACHE_EXPIRATION_SECS = 0
#HTTPCACHE_DIR = 'httpcache'
#HTTPCACHE_IGNORE_HTTP_CODES = []
#HTTPCACHE_STORAGE = 'scrapy.extensions.httpcache.FilesystemCacheStorage'

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@ -0,0 +1,4 @@
# This package will contain the spiders of your Scrapy project
#
# Please refer to the documentation for information on how to create and manage
# your spiders.

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@ -0,0 +1,66 @@
# -*- coding: utf-8 -*-
import scrapy
from urllib.parse import urlencode
from urllib.parse import urljoin
import re
import json
queries = ['iphone']
API = ''
def get_url(url):
payload = {'api_key': API, 'url': url, 'country_code': 'us'}
proxy_url = 'http://api.scraperapi.com/?' + urlencode(payload)
return proxy_url
class AmazonSpider(scrapy.Spider):
name = 'amazon'
def start_requests(self):
for query in queries:
url = 'https://www.amazon.de/s?' + urlencode({'k': query})
yield scrapy.Request(url=url, callback=self.parse_keyword_response)
def parse_keyword_response(self, response):
products = response.xpath('//*[@data-asin]')
for product in products:
asin = product.xpath('@data-asin').extract_first()
product_url = f"https://www.amazon.de/dp/{asin}"
yield scrapy.Request(url=product_url, callback=self.parse_product_page, meta={'asin': asin})
next_page = response.xpath('//li[@class="a-last"]/a/@href').extract_first()
if next_page:
url = urljoin("https://www.amazon.de", next_page)
yield scrapy.Request(url=url, callback=self.parse_keyword_response)
def parse_product_page(self, response):
asin = response.meta['asin']
title = response.xpath('//*[@id="productTitle"]/text()').extract_first()
image = re.search('"large":"(.*?)"', response.text).groups()[0]
rating = response.xpath('//*[@id="acrPopover"]/@title').extract_first()
number_of_reviews = response.xpath('//*[@id="acrCustomerReviewText"]/text()').extract_first()
price = response.xpath('//*[@id="priceblock_ourprice"]/text()').extract_first()
if not price:
price = response.xpath('//*[@data-asin-price]/@data-asin-price').extract_first() or \
response.xpath('//*[@id="price_inside_buybox"]/text()').extract_first()
temp = response.xpath('//*[@id="twister"]')
sizes = []
colors = []
if temp:
s = re.search('"variationValues" : ({.*})', response.text).groups()[0]
json_acceptable = s.replace("'", "\"")
di = json.loads(json_acceptable)
sizes = di.get('size_name', [])
colors = di.get('color_name', [])
bullet_points = response.xpath('//*[@id="feature-bullets"]//li/span/text()').extract()
seller_rank = response.xpath(
'//*[text()="Amazon Best Sellers Rank:"]/parent::*//text()[not(parent::style)]').extract()
yield {'asin': asin, 'Title': title, 'MainImage': image, 'Rating': rating, 'NumberOfReviews': number_of_reviews,
'Price': price, 'AvailableSizes': sizes, 'AvailableColors': colors, 'BulletPoints': bullet_points,
'SellerRank': seller_rank}

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@ -2,3 +2,4 @@ pymysql
flask
flask-sqlalchemy
flask_restful
scrapy

11
Crawler/scrapy.cfg Normal file
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@ -0,0 +1,11 @@
# Automatically created by: scrapy startproject
#
# For more information about the [deploy] section see:
# https://scrapyd.readthedocs.io/en/latest/deploy.html
[settings]
default = crawler.settings
[deploy]
#url = http://localhost:6800/
project = crawler