Network

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Network#

Short network snippets the operator pastes into a shell or notebook. urllib and socket ship with Python; httpx is the recommended third-party HTTP client.

GET a URL and read the body as text (stdlib).

import urllib.request
body = urllib.request.urlopen("https://example.com/").read().decode()

GET with httpx (async-capable, modern API).

import httpx
r = httpx.get("https://example.com/", timeout=5.0)
r.raise_for_status()
body = r.text

POST a JSON body.

r = httpx.post("https://api.example/items",
               json={"name": "x"}, timeout=5.0)

Stream a large download to disk.

with httpx.stream("GET", url) as r, open("dump.bin", "wb") as f:
    for chunk in r.iter_bytes():
        f.write(chunk)

Open a TCP connection with a deadline.

import socket
sock = socket.create_connection(("example.com", 443), timeout=3)

Quick TCP port probe (returns True if open).

import socket
def is_open(host: str, port: int, timeout: float = 1.0) -> bool:
    try:
        with socket.create_connection((host, port), timeout=timeout):
            return True
    except OSError:
        return False

Resolve a hostname.

addrs = socket.gethostbyname_ex("example.com")[2]

Reverse-resolve an IP.

name, *_ = socket.gethostbyaddr("8.8.8.8")

CIDR membership test with ipaddress.

import ipaddress
if ipaddress.ip_address("10.0.0.42") in ipaddress.ip_network("10.0.0.0/8"):
    internal()

Enumerate every host in a network.

for ip in ipaddress.ip_network("192.168.1.0/29").hosts():
    check(ip)

Parse a URL.

from urllib.parse import urlparse
u = urlparse("https://op:pw@example.com:8443/path?x=1#f")
u.scheme, u.hostname, u.port, u.path, u.query, u.fragment

Build a query string from a dict.

from urllib.parse import urlencode
qs = urlencode({"q": "search term", "page": 2})

References#

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