A campsaver crawler to watch the price of the commodity you want to have

campsaver.py

#!/usr/bin/env python3
#
# Copyright 2017, Taihsiang Ho  <[email protected]>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
# may be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
#
# Mail service should only be run from a system with postfix installed.
# e.g. sudo apt-get install postfix on Ubuntu Xenial
#
import logging
import requests
from bs4 import BeautifulSoup
# For mail notification service
import os
import smtplib
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText

CAMPSAVER_URL = 'https://www.campsaver.com/'
ITEM_SOTO_OD_1RX = 'soto-od-1rx-windmaster-stove-with-4-flex-pot-support.html'
THRESHOLD_PRICE = 55.0
THRESHOLD_PERCENTAGE = 0.75
SENT_FROM = '[email protected]'
SENT_TO = '[email protected]'

SMTPSERVER = os.environ.get('SMTP_SERVER', 'localhost')

ERROR_MSG = """
ERROR!
The email for this job was supposed to be located in {} but that file
wasn't generated for some reason. This almost never happens, so
look for something farther up in the job related to this subject for
clues as to what might have happened
"""

format_str = "[ %(funcName)s() ] %(message)s"
logging.basicConfig(level=logging.INFO, format=format_str)


def mailit(subject, content_text, sent_from, sent_to):
    msg = MIMEMultipart()

    body = MIMEText(content_text)
    msg.attach(body)

    msg['Subject'] = subject
    msg['From'] = sent_from
    msg['To'] = sent_to

    s = smtplib.SMTP(SMTPSERVER)
    s.send_message(msg)
    s.quit()


def is_threshold_price(source, target):
    logging.debug("source is %f" % source)
    logging.debug("target is %f" % target)
    if source < target or source == target:
        return True
    else:
        return False


def is_threshold_percentage(original, sale, target):
    sale_percentage = float(sale) / original
    logging.debug(sale_percentage)
    logging.debug(target)
    return is_threshold_price(sale_percentage, target)


def is_threshold(commodity):
    price_original = commodity['price_original']
    price_sale = commodity['price_sale']
    flag_price = is_threshold_price(price_sale, THRESHOLD_PRICE)
    logging.debug("flag_price is %r" % flag_price)
    flag_percentage = is_threshold_percentage(price_original, price_sale, THRESHOLD_PERCENTAGE)
    logging.debug("flag_percentage is %r" % flag_percentage)
    return flag_price or flag_percentage


def get_web_page(url, item_entry):
    resp = requests.get(url + item_entry)
    if resp.status_code != 200:
        print('Invalid url:', resp.url)
        return None
    else:
        return resp.text


def get_commodity_info(dom):
    soup = BeautifulSoup(dom, 'html5lib')
    commodity = dict()
    commodity['name'] = soup.title.text.strip()
    prices_dict = soup.find(id='fancy-options').span.attrs
    try:
        commodity['price_original'] = float(prices_dict['data-variant-price'])
    except ValueError:
        logging.warning('data-variant-price is not found. Try content.')
        commodity['price_original'] = float(prices_dict['content'])
    commodity['price_sale'] = float(prices_dict['data-variant-sale'])
    # commodity['current_price'] = soup.find(id='fancy-options').span.contents[1].contents[0].split('$')[1]
    commodity['notification'] = is_threshold(commodity)
    return commodity


if __name__ == '__main__':
    page = get_web_page(CAMPSAVER_URL, ITEM_SOTO_OD_1RX)
    if page:
        commodity = get_commodity_info(page)
        # show summary
        logging.debug(commodity['name'])
        for k, v in commodity.items():
            if k != 'name':
                logging.debug("%s %s" % (k, v))

        # nofity the team if the price hits the targets
        if commodity['notification']:
            logging.info('Hit the target price. Mail notification.')
            subject = commodity['name'] + ' hits the target price'
            content_text = """
Your commodity meets your expectation {} or {} of the original price.

Click the link to go to the commodity page:

"""
            content_text += CAMPSAVER_URL + ITEM_SOTO_OD_1RX
            content_text.format(THRESHOLD_PRICE, THRESHOLD_PERCENTAGE)
            mailit(subject, content_text, SENT_FROM, SENT_TO)
        else:
            logging.info('Does not hit the target price. Do nothing.')
    else:
        # if there is no page, nofity maintainers
        logging.warning('No page. Mail notification.')
        mailit("No Campsaver watching page", CAMPSAVER_URL + ITEM_SOTO_OD_1RX, SENT_FROM, SENT_TO)

requirements.txt

html5
requests
bs4