Implementing a simple asynchronous web scraper using asyncio.**
- **Solution:** Use asyncio to fetch multiple web pages concurrently, parse their content, and extract relevant information.To implement a simple asynchronous web scraper using asyncio and incorporating the Factory Method design pattern, we can define an interface for web page scraping and concrete scraper classes for different websites. Here's how we can do it:
```python
import asyncio
import aiohttp
from abc import ABC, abstractmethod
class WebScraper(ABC):
@abstractmethod
async def scrape(self):
pass
class WikipediaScraper(WebScraper):
async def scrape(self):
async with aiohttp.ClientSession() as session:
async with session.get('https://en.wikipedia.org/wiki/Main_Page') as response:
html = await response.text()
# Add parsing logic here
print("Scraped content from Wikipedia:", html[:100])
class RedditScraper(WebScraper):
async def scrape(self):
async with aiohttp.ClientSession() as session:
async with session.get('https://www.reddit.com/') as response:
html = await response.text()
# Add parsing logic here
print("Scraped content from Reddit:", html[:100])
class WebScraperFactory:
@staticmethod
def get_scraper(scraper_type):
if scraper_type == 'Wikipedia':
return WikipediaScraper()
elif scraper_type == 'Reddit':
return RedditScraper()
else:
raise ValueError("Invalid scraper type")
async def main():
scraper_types = ['Wikipedia', 'Reddit']
scrapers = [WebScraperFactory.get_scraper(scraper_type) for scraper_type in scraper_types]
tasks = [scraper.scrape() for scraper in scrapers]
await asyncio.gather(*tasks)
asyncio.run(main())
```
In this solution:
- We define the `WebScraper` interface with an abstract method `scrape()`, which concrete scraper classes must implement.
- `WikipediaScraper` and `RedditScraper` are concrete scraper classes that implement the `scrape()` method to scrape content from Wikipedia and Reddit, respectively.
- The `WebScraperFactory` class provides a factory method `get_scraper()` to create instances of specific scraper classes based on the provided scraper type.
- In the `main()` function, we create instances of scraper classes using the factory method, and then asynchronously call the `scrape()` method for each scraper using asyncio.
This solution demonstrates the use of the Factory Method design pattern to create web scraper objects dynamically based on the provided type, allowing for easy extension and addition of new scraper types in the future.
