hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

P7h

tmux vs. screen commands

---

Action	tmux	screen
start a new session	tmux tmux new tmux new-session	screen
start a new session with a name	tmux new -s name	screen -S name
re-attach a detached session	tmux attach tmux attach-session	screen -r
re-attach a detached session with a name	tmux attach -t name tmux a -t name	screen -r name
re-attach an attached session (detaching it from elsewhere)	tmux attach -dtmux attach-session -d	screen -dr

EdwardBetts

from pprint import pformat
from typing import Any

from pygments import highlight
from pygments.formatters import Terminal256Formatter
from pygments.lexers import PythonLexer


def pprint_color(obj: Any) -> None:
    """Pretty-print in color."""

roaldnefs

# Install XQuartz
brew cask install xquartz

# Restart MacOS

# Open XQuartz
open -a XQuartz

# Ensure the "Allow connections from network clients" option in Preferences >> Security is turned on

csrutil

#!/bin/bash                                                                                                                                                                                                                                                                                                              
                                                                                                                                                                                                                                                                                                                         
country_block=(china bangladesh cambodia hongkong india iran iraq jordan korea kuwait malysia morocco oman pakistan qatar saudi singapore sudan thailand taiwan emirates vietnam turkey)                                                                                                                                 
                                                                                  

CMCDragonkai

Python subprocess.run and argparse nargs (multi-value options) is tricky

If you have a Python program that uses argparse nargs to specify multi-value options then you need to make sure that each value is its own parameter.

import subprocess

subprocess.run(
    [
 'command',