gracyvscolly
Gracy is an API client library based on httpx that provides an extra stability layer with:
- Retry logic
- Logging
- Connection throttling
- Tracking/Middleware
In web scraping, Gracy can be a convenient tool for creating scraper based API clients.
Colly is a popular web scraping library for the Go programming language. It's designed to be fast and easy to use, and it provides a simple and flexible API for traversing and extracting information from websites.
Colly supports:
- Concurrent scraping with a simple API
- Automatic handling of cookies and sessions
- Automatic handling of redirects
- Support for parsing HTML and XML
- Support for parsing JSON and binary data
- Support for custom storage (e.g. scraping results to a database)
- Simple JavaScript rendering with Colly's built-in rendering engine.
Colly also provides several optional features, such as support for user-agents, delay between requests, rate-limiting and proxy usage.
Colly's API is quite simple, and it is easy to get started with basic web scraping tasks. It's a good choice for scraping moderate to heavy sites, and it can be useful for a wide range of use cases, such as data mining, content extraction, and more.
Additionally, you can use it together with Goquery, a library that allow you to make jquery like queries on HTML documents and it is often used together with Colly to ease the way of parsing the HTML.
Highlights
Example Use
# 0. Import
import asyncio
from typing import Awaitable
from gracy import BaseEndpoint, Gracy, GracyConfig, LogEvent, LogLevel
# 1. Define your endpoints
class PokeApiEndpoint(BaseEndpoint):
GET_POKEMON = "/pokemon/{NAME}" # 👈 Put placeholders as needed
# 2. Define your Graceful API
class GracefulPokeAPI(Gracy[str]):
class Config: # type: ignore
BASE_URL = "https://pokeapi.co/api/v2/" # 👈 Optional BASE_URL
# 👇 Define settings to apply for every request
SETTINGS = GracyConfig(
log_request=LogEvent(LogLevel.DEBUG),
log_response=LogEvent(LogLevel.INFO, "{URL} took {ELAPSED}"),
parser={
"default": lambda r: r.json()
}
)
async def get_pokemon(self, name: str) -> Awaitable[dict]:
return await self.get(PokeApiEndpoint.GET_POKEMON, {"NAME": name})
# Note: since Gracy is based on httpx we can customized the used client with custom headers etc"
def _create_client(self) -> httpx.AsyncClient:
client = super()._create_client()
client.headers = {"User-Agent": f"My Scraper"}
return client
pokeapi = GracefulPokeAPI()
async def main():
try:
pokemon = await pokeapi.get_pokemon("pikachu")
print(pokemon)
finally:
pokeapi.report_status("rich")
asyncio.run(main())
package main
import (
"fmt"
"github.com/gocolly/colly/v2"
)
func main() {
// Instantiate default collector
c := colly.NewCollector(
// Visit only domains: hackerspaces.org, wiki.hackerspaces.org
colly.AllowedDomains("hackerspaces.org", "wiki.hackerspaces.org"),
)
// On every a element which has href attribute call callback
c.OnHTML("a[href]", func(e *colly.HTMLElement) {
link := e.Attr("href")
// Print link
fmt.Printf("Link found: %q -> %s\n", e.Text, link)
// Visit link found on page
// Only those links are visited which are in AllowedDomains
c.Visit(e.Request.AbsoluteURL(link))
})
// Before making a request print "Visiting ..."
c.OnRequest(func(r *colly.Request) {
fmt.Println("Visiting", r.URL.String())
})
// Start scraping on https://hackerspaces.org
c.Visit("https://hackerspaces.org/")
}