随机应变 ABCD: Always Be Coding and … : хороший
watch out image compression level and natural width.
should be less pixels.
Total bits = pixel x bit per pixel
body {
margin: 0;
}
img {
float: left;
margin-right: 10px;
width: calc((100% - 20px)/3);
}
img:last-of-type {
margin-right: 0;
}
Vector scales without quality degradation.
$0.naturalWidth 601 $0.naturalWidth 1202
Characters -> Tokens -> Nodes -> DOM
Request page -> GET html -> page head(build DOM, render) -> search result(build DOM, render)
Characters -> Tokens -> Nodes -> CSSOM
hi tag is faster evaluation than div p tag as dom tree.
JavaScript is parser blocking
Async is a utility module which provides straight-forward, powerful functions for working with asynchronous JavaScript. Although originally designed for use with Node.js and installable via npm install –save async, it can also be used directly in the browser.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<canvas id="my_canvas"></canvas>
</body>
<script>
var canvas = null;
var context = null;
setup = function(){
canvas = document.getElementById("my_canvas");
context = canvas.getContext('2d');
canvas.width = 1200;
canvas.height = 720;
};
</script>
</html>
<style tyle="text/css">
.container {
width: 100%;
display: flex;
flex-wrap: wrap;
}
.box {width: 150px;}
</style>
column drop, off canvas, layout shifter, mostly fluid
<link rel="stylesheet" href="styles.css"> <link rel="stylesheet" media="screen and (min-width:500px)" href="over500.css">
media query within a style sheet.
@media screen and (min-width: 500px){
body { color: #F79420; }
}
@media screen and (min-width: 800px){
body { background-color: blue; }
}
frequently used max-width and min-width
@media screen and (max-width: 500px){
.yes {
opacity: 1;
}
. no {
opacity: 0;
}
}
change background-color with width.
body {
background-color: green;
}
@media screen and (max-width: 400px) {
body {
background-color: red;
}
}
@media screen and (min-width: 600px) {
body {
background-color: blue;
}
}
developer tool help you to decide media query
<meta name="viewport" content="width=device-width, initial-scale=1">
initial-scale indicate relationship between device independent pixel and css pixel.
<meta name="viewport" content="width=360,initial-scale=1">
prevent image overflow content
img, embed, object, video {
max-width: 100%
}
example
<img id="owl">
#owl {
width: 640px;
max-width: 100%;
}
CSS/Properties
https://www.w3.org/community/webed/wiki/CSS/Properties
nav a, button {
min-width: 48px;
max-height: 48px;
}
device pixel ratio:デバイス・ピクセルとCSSピクセルの比率のこと
The device pixel ratio is the ratio between physical pixels and logical pixels. For instance, the iPhone 4 and iPhone 4S report a device pixel ratio of 2, because the physical linear resolution is double the logical linear resolution.
device pixel / hardware pixel: デバイス・端末がサポートする物理的な最小単位のピクセル。ハードウェア・ピクセルともいう。
CSS pixel:CSSで使う論理上のピクセル。デバイス・ピクセルが物理的なピクセルの数であるのに対し、CSSピクセルは論理上のピクセルの数です。
CSS properties take “length” values, such as width, margin, padding, font-size, border-width, etc.Length is a number followed by a length unit, such as 10px, 2em, etc.
A whitespace cannot appear between the number and the unit. However, if the value is 0, the unit can be omitted.For some CSS properties, negative lengths are allowed.
There are two types of length units: relative and absolute.
User agent：利用者があるプロトコルに基づいてデータを利用する際に用いるソフトウェアまたはハードウェアのこと。 特にHTTPを用いてWorld Wide Webにアクセスする、ウェブブラウザなどのソフトウェアのこと。
In computing, a user agent is software (a software agent) that is acting on behalf of a user. One common use of the term refers to a web browser telling a web site information about the browser and operating system.
Example:Mozilla/5.0 (Linux; Android 5.0; Nexus 6 Build/XXX00x) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.59 Mobile Safari/537.36
Google dev tool remote debugging
https://developers.google.com/web/tools/chrome-devtools/remote-debugging/
Hardware Pixel and Device Independent Pixel
With font boosting and without font boosting
ViewPortとは：「表示領域」
スケールは1、等倍で表示される
ポートレート表示時の幅は320px
ランドスケープ表示時の幅は480px以上
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="..."> <title>title here</title> ... </head> <body> ...
1920 x 1980 px
DPR = 2
maximum width of a viewport is 960px
var amy = {loc:1};
move(amy);
var ben = {loc:9};
move(ven);
var move = function(car){
car.loc++;
};
var gold = {a:1};
var blue = extend({}, gold);
var rose = Object.create(gold);
gold.z = 3
log(blue.z); //undefined
log(rose.z); //3
var = {}
this indicate in memory variable.
https://developers.google.com/maps/documentation/geocoding/get-api-key
import httplib2
import json
def getGeocodeLocation(inputString):
google_api_key = "your_key"
locationString = inputString.replace(" ", "+")
url = ('https://maps.googleapis.com/maps/api/geocode/json?address=%s&key=%s'% (
locationString, google_api_key))
h = httplib2.Http()
response, content = h.request(url, 'GET')
result = json.loads(content)
latitude = result['result'][0]['geometry']['location']['lat']
longitude = result['result'][0]['geometry']['location']['lng']
return(latitude,longitude)
flask
from flask import Flask app = Flask(__name__) def puppyFunction(): return "Yes, puppies!" def puppiesFunction(id) return "This method will act on the puppy with id %s" % id if __name__ == '__main__': app.debug = True app.run(host='0.0.0.0', port=5000)
from sqlalchemy import Column, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, sessionmaker
from sqlalchemy import create_engine
from passlib.apps import custom_app_context as pwd_context
Base = declarative_base()
class User(Base):
__tablename__ = 'user'
id = Column(Integer, primary_key=True)
username = Column(String(32), index=True)
password_hash = Column(String(64))
engine = create_engine('sqlite:///users.db')