Tutorial on Web Scraping with Python, NoSQL, and FastAPI with Scheduled Execution

In this tutorial, we will cover how to build a web scraping application using Python, NoSQL, and FastAPI. We will use FastAPI to create a simple web server that scrapes a website on a schedule and saves the data to a NoSQL database.

Prerequisites

To follow along with this tutorial, you will need the following tools installed on your machine:

• Python 3.x
• FastAPI
• MongoDB (or any other NoSQL database of your choice)
• Requests library
• APScheduler

Step 1: Setup the environment

First, create a new directory for your project and create a virtual environment inside it. You can do this by running the following commands:

mkdir web_scraping_app
cd web_scraping_app
python3 -m venv venv

Step 2: Install dependencies

Activate the virtual environment by running:

source venv/bin/activate

Then, install the required libraries using pip:

pip install fastapi uvicorn pymongo requests apscheduler

Step 3: Create a scraper module

Create a new Python module called scraper.py and add the following code to it:

import requests
from bs4 import BeautifulSoup

def scrape_website(url):
    response = requests.get(url)
    soup = BeautifulSoup(response.text, 'html.parser')

    # Add your scraping logic here

    return data

Step 4: Set up the FastAPI app

Create a new Python module called main.py and add the following code to it:

from fastapi import FastAPI
from apscheduler.schedulers.background import BackgroundScheduler
from scraper import scrape_website

app = FastAPI()

scheduler = BackgroundScheduler()
scheduler.start()

@app.on_event("startup")
def start_scheduler():
    scheduler.add_job(scrape_website, "interval", hours=1, args=[url])

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)

Step 5: Connect to the NoSQL database

Modify the scraper.py module to save the scraped data to a NoSQL database. For example, if you are using MongoDB, you can add the following code to the module:

import pymongo

client = pymongo.MongoClient("mongodb://localhost:27017/")
db = client["web_scraping_app"]
collection = db["scraped_data"]

def save_to_database(data):
    collection.insert_one(data)

Step 6: Run the application

Start the FastAPI server by running:

python main.py

Your web scraping application will now run on a schedule, scraping the website every hour and saving the data to the NoSQL database.

Conclusion

In this tutorial, we have seen how to build a web scraping application using Python, NoSQL, and FastAPI. You can customize this application by adding more complex scraping logic, using a different NoSQL database, or scheduling the scraping at different intervals. Happy coding!