Amazon price alert

Poll an Amazon sale page (or multiple pages) for a maximum price and send yourself an email if the price check passes.

Installation

Clone the repository. This code was written for python 3 (3.6.3), you should also have pip installed.

• To install required libraries:

pip install --user -r requirements.txt

note that one the libraries used is the lxml library, which requires a couple of extra packages on Ubuntu:

[sudo] apt install libxml2-dev libxslt-dev

Configuration

Configuration is held in json format, config.json is used by default and has some configuration for reference, but a different file can be passed using the command line flags. you must set your email credentials. Required configuration:

• email (dictionary) - this is the configuration for the email server and credentials to use for sending out the email.

  • smtp_url - smtp server to use (default: smtp.gmail.com:587)
  • user - the email address to be used for authentication
  • password - the password to be used for authentication (if you have 2FA set up on your account, take a look at app passwords)

• base_url (string) - the base amazon url of the sales page, differs among the different variants of amazon.

• xpath_selector (string) - the xpath selector of the element holding the price in the sale page, the default is true for all amazon variants that have been tested so far (default: //*[@id='priceblock_ourprice'])

• items (array) - an array of items, each item should be an array as follows:

  [amazon_item_id_string, price_in_integer]

Running the script

$ ./price-alert.py --help
usage: price-alert.py [-h] [-c CONFIG] [-t POLL_INTERVAL]

optional arguments:
  -h, --help            show this help message and exit
  -c CONFIG, --config CONFIG
                        Configuration file path
  -t POLL_INTERVAL, --poll-interval POLL_INTERVAL
                        Time in seconds between checks

when running without any arguments, the script will use config.json for configuration and the default polling interval of 30 seconds.

Other sale pages/email client

The script was tested on Amazon, so if you try running it on a different site make sure that xpath_selector is set correctly in the configuration json and that the price check itself is correct. The smtp client is configured for Gmail, so be sure to change it if you're using a different one.

TODO

• add tests
• add CI
• override configuration via arguments/environment variables