pycurlvsem-http-request
PycURL is a Python interface to libcurl, a multi-protocol file transfer library written in C. PycURL allows developers to use a variety of network protocols in their Python programs, including HTTP, FTP, SMTP, POP3, and many more.
PycURL is often used in web scraping, data analysis, and automation tasks, as it allows developers to send and receive data over the internet. It can be used to perform various types of requests, such as GET, POST, PUT, and DELETE, and can also handle file uploads and downloads, cookies, and redirects.
One of the key features of PycURL is its support for SSL and proxy servers, which allows developers to securely transfer data over the internet and work around any network restrictions. PycURL also supports a wide range of authentication methods, such as Basic, Digest, and NTLM, and allows developers to easily set custom headers and query parameters.
Just like cURL itself, PycURL is also highly configurable and allows for fine-grained control over various aspects of the transfer, such as timeouts, retries, buffer sizes, and verbosity levels. Additionally, PycURL also provides easy access to the underlying libcurl library, which allows developers to access advanced functionality that is not exposed by the PycURL API.
It's important to note that PycURL is a wrapper around the libcurl library and therefore provides the same functionality and performance as libcurl.
Main strengths of PycURL is that it uses cURL which is one of the most feature rich low-level http clients. The downside is that it's a very low-level client (see the examples below) with complex API making use in web scraping very difficult and niche.
em-http-request is a Ruby gem for making asynchronous HTTP requests using EventMachine. It allows you to perform multiple requests simultaneously and handle the responses as they come in, rather than waiting for each request to complete before making the next one.
In short it supports: - Asynchronous HTTP API for single & parallel request execution - Keep-Alive and HTTP pipelining support - Auto-follow 3xx redirects with max depth - Automatic gzip & deflate decoding - Streaming response processing - Streaming file uploads - HTTP proxy and SOCKS5 support - Basic Auth & OAuth - Connection-level & global middleware support - HTTP parser via http_parser.rb - Works wherever EventMachine runs: Rubinius, JRuby, MRI
Highlights
Example Use
import pycurl
from io import BytesIO
buf = BytesIO()
headers = BytesIO()
c = pycurl.Curl()
c.setopt(c.HTTP_VERSION, c.CURL_HTTP_VERSION_2_0) # set to use http2
# set proxy
c.setopt(c.PROXY, 'http://proxy.example.com:8080')
c.setopt(c.PROXYUSERNAME, 'username')
c.setopt(c.PROXYPASSWORD, 'password')
# make a request
c.setopt(c.URL, 'https://httpbin.org/get')
c.setopt(c.WRITEFUNCTION, buf.write) # where to save response body
c.setopt(c.HEADERFUNCTION, headers.write) # where to save response headers
# to make post request enable POST option:
# c.setopt(c.POST, 1)
# c.setopt(c.POSTFIELDS, 'key1=value1&key2=value2')
c.perform() # send request
# read response
data = buf.getvalue().decode()
headers = headers.getvalue().decode() # headers as a string
headers = dict([h.split(': ') for h in headers.splitlines() if ': ' in h]) # headers as a dict
c.close()
# multiple concurrent requests can be made using CurlMulti object:
# Create a CurlMulti object
multi = pycurl.CurlMulti()
# Set the number of maximum connections
multi.setopt(pycurl.MAXCONNECTS, 5)
# Create a list to store the Curl objects
curls = []
# Add the first request
c1 = pycurl.Curl()
c1.setopt(c1.URL, 'https://httpbin.org/get')
c1.setopt(c1.WRITEFUNCTION, BytesIO().write)
multi.add_handle(c1)
curls.append(c1)
# Add the second request
c2 = pycurl.Curl()
c2.setopt(c2.URL, 'https://httpbin.org/')
c2.setopt(c2.WRITEFUNCTION, BytesIO().write)
multi.add_handle(c2)
curls.append(c2)
# Start the requests
while True:
ret, _ = multi.perform()
if ret != pycurl.E_CALL_MULTI_PERFORM:
break
# Close the connections
for c in curls:
multi.remove_handle(c)
c.close()
EventMachine.run {
http = EventMachine::HttpRequest.new('http://google.com/').get :query => {'keyname' => 'value'}
# add callback for errors:
http.errback { p 'Uh oh'; EM.stop }
# add callback for successful requests
http.callback {
p http.response_header.status
p http.response_header
p http.response
EventMachine.stop
}
}