Web Valueist

Documentation Website

Fetches a value from the web, compares it with a given value and exits with zero exit code if the condition is satisfied

Table of Contents

• Installation
• Usage
  • Library
  • CLI
    • Sample Usage
    • Debugging
    • JSON Output
    • Using Quantifiers
    • Sample cron job
• Development setup from repository

Installation

You can install web-valueist from PyPI using your preferred package manager:

pip:

pip install web-valueist

Poetry:

poetry add web-valueist

uv:

uv pip install web-valueist

pipenv:

pipenv install web-valueist

Usage

Library

You can import and use web_valueist directly in your Python code without relying on the CLI. The evaluate function returns a dictionary indicating whether the condition was met, along with the parsed values.

import web_valueist

result = web_valueist.evaluate(
    url="http://example.com",
    selector="h1",
    parser_name="str",
    operator_name="eq",
    value="Example Domain",
    quantifier="ANY" # Optional, defaults to "ANY"
)

if result["success"]:
    print(f"Match found! Fetched value: {result['value']}")
else:
    print("Condition not met.")

CLI

web_valueist [-h] [--debug] [--json] url parser_name [quantifier] selector operator_name value

positional arguments:
  url
  parser_name
  quantifier      Optional: ANY or EVERY (default: ANY)
  selector
  operator_name
  value

options:
  -h, --help      show this help message and exit
  --debug         Show debug logs including found values
  --json          Output input and result as JSON

Sample Usage

By default, web_valueist is silent and communicates success or failure via the exit code.

Sample success

python -m web_valueist https://www.ikea.com.cy/en/products/fjallhavre-duvet-warm-240x220-cm/70458057/ int span.price__integer ">" 240

( you can also use gt instead of ">")

Exit Code: 0

Sample failure

python -m web_valueist https://www.ikea.com.cy/en/products/fjallhavre-duvet-warm-240x220-cm/70458057/ int span.price__integer "<" 240

( you can also use lt instead of "<")

Exit Code: 1

Debugging

Use the --debug flag to see the values fetched from the web.

python -m web_valueist https://www.ikea.com.cy/en/products/fjallhavre-duvet-warm-240x220-cm/70458057/ int span.price__integer ">" 240 --debug

Output:

DEBUG:web_valueist.lib:Found value ['245']

JSON Output

Use the --json flag to get a structured output.

python -m web_valueist http://example.com str h1 "eq" "Example Domain" --json

Output:

{"args": {"url": "http://example.com", "parser_name": "str", "quantifier": "ANY", "selector": "h1", "operator_name": "eq", "value": "Example Domain"}, "result": {"success": true, "value": "Example Domain"}}

Using Quantifiers

When a selector matches multiple elements, you can use ANY or EVERY.

• ANY (default): At least one selector match needs to satisfy the condition.
• EVERY: All selector matches need to satisfy the condition.

Example using EVERY:

python -m web_valueist https://example.com int EVERY .price ">" 100

If no quantifier is specified, ANY is used by default.

Sample cron job

*/30 * * * * web_valueist "https://www.bazaraki.com/car-motorbikes-boats-and-parts/cars-trucks-and-vans/mazda/mazda-mx5/year_min---71/?ordering=cheapest&lat=35.01804869361969&lng=34.04709596563199&radius=5000&price_max=30000" int .advert__content-price._not-title   "<" 22500 &&message="Some fancy car matching your criteria was found" &&if command -v notify-send >/dev/null 2>&1 ; then notify-send "$message"; else say "$message"; fi

Development setup from repository

While in project directory:

./install.sh

Maintainer: csmonk