<script type="text/javascript" src="delighters.js">

<div class="foo" data-delighter></div>

/* 初始 */
.foo.delighter {
  transition: all 0.3s ease-out;
  transform: translateX(-100%);
  opacity: 0;
}
/* 动画开始 当元素top处于viewpoint 75%处时触发 */
.foo.delighter.started {
  transform: none;
  opacity: 1;
}
/* 动画结束 当元素bottom处于viewpoint 75%处时触发 */
.foo.delighter.started.ended {
  border: solid red 10px;
}

<button>☰</button>

<nav class="menu">
  <ul>
    <li>
      <button onclick="alert('Hello there!')">
        Display Greeting
      </button>
    </li>
    <li>
      <button onclick="print()">
        Print This Page
      </button>
    </li>
  </ul>
</nav>

.menu {
  visibility: hidden;
}
/**
当点击按钮触发focus时显示菜单，
显示后菜单后点击菜单会触发菜单的active,
这时也要显示，否则菜单按钮无法点击
*/
button + .menu:active,
button:focus + .menu {
  visibility: visible;
}

<div class="max-w-sm mx-auto flex p-6 bg-white rounded-lg shadow-xl">
  <div class="flex-shrink-0">
    <img class="h-12 w-12" src="/img/logo.svg" alt="ChitChat Logo" />
  </div>
  <div class="ml-6 pt-1">
    <h4 class="text-xl text-gray-900 leading-tight">ChitChat</h4>
    <p class="text-base text-gray-600 leading-normal">
      You have a new message!
    </p>
  </div>
</div>

@font-face {
  font-family: 'my-font';
  /* 当我们将font-display的值设置为swap的时候，
  最开始会先使用系统字体来显示文字，当自定义字体下
  载完毕后，自定义字体就会取代系统字体。*/
  font-display: swap;
  src: url(my-font.woff2) format('woff2');
}

<link
  href="https://fonts.googleapis.com/css?family=Lobster&display=swap"
  rel="stylesheet"
/>

// 创建1000个数字实例
const dots = Ola(Array(1000).fill(0));

// 每600毫秒更新所有
setInterval(
  () =>
    dots.forEach((dot, i) => {
      dots[i] = Math.random();
    }),
  600
);

> python uds.py push Ubuntu.Desktop.16.04.iso
Ubuntu.Desktop.16.04.iso 需要 543 个文档来保存.
创建父目录成功 ID 1fc6JGpX6vUWiwflL1jBxM1YpuMHFAms8
上传成功 Ubuntu.Desktop.16.04.iso: [██████████████████████████████] 100%

import time
from functools import lru_cache
@lru_cache(maxsize=512)
def fib_memoization(number: int) -> int:
    if number == 0: return 0
    if number == 1: return 1
    
    return fib_memoization(number-1) + fib_memoization(number-2)
start = time.time()
fib_memoization(40)
print(f'Duration: {time.time() - start}s')
# Duration: 6.866455078125e-05s

from pathlib import Path
root = Path('post_sub_folder')
print(root)
# post_sub_folder
path = root / 'happy_user'
# 获得绝对路径
print(path.resolve())
# /home/somefolder/post_sub_folder/happy_user

def sentence_has_animal(sentence: str) -> bool:
  return "animal" in sentence
sentence_has_animal("Donald had a farm without animals")
# True

from enum import Enum, auto
class Monster(Enum):
    ZOMBIE = auto()
    WARRIOR = auto()
    BEAR = auto()
    
print(Monster.ZOMBIE)
# Monster.ZOMBIE

head, *body, tail = range(5)
print(head, body, tail)
# 0 [1, 2, 3] 4
py, filename, *cmds = "python3.7 script.py -n 5 -l 15".split()
print(py)
print(filename)
print(cmds)
# python3.7
# script.py
# ['-n', '5', '-l', '15']
first, _, third, *_ = range(10)
print(first, third)
# 0 2

./python.exe
Python 3.8.0a4+ (heads/master:88db8bd064, May  9 2019, 15:54:59)
[Clang 7.0.2 (clang-700.1.81)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> name = "karthikeyan"
>>> f"name={name}"
'name=karthikeyan'
>>> f"{name=}"
"name='karthikeyan'"