traderbagel

/* event定義中的 keyword `indexed` 會被放在 topics當成參數做查詢, topics最多有四個, 第一個保留為 event的 hash值(識別用) */
event Transfer(address indexed from, address indexed to, uint256 value);

/* Send coins */
function transfer(address _to, uint256 _value) {
  if (_to == 0x0) throw;                               // Prevent transfer to 0x0 address. Use burn() instead
  if (_value <= 0) throw;
  if (balanceOf[msg.sender] < _value) throw;           // Check if the sender has enough
  if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
    balanceOf[msg.sender] = SafeMath.safeSub(balanceOf[msg.sender], _value);              // Subtract from the sender

traderbagel

# 1. get deleted value 
my_dict.pop('key', None)

# 2. simple but not atomic 
if 'key' in my_dict: del my_dict['key']

# 3. atomic
try:
    del my_dict['key']
except KeyError:

traderbagel

# tuple
single_tuple = (1,)  

# integer
# Python thinks it's part of a mathematical operation and has precedence
not_tuple = (1)

traderbagel

import time
import base64
import json
import hmac
import hashlib
import requests

URL = 'https://api.bitfinex.com'
API_VERSION = '/v1'
API_KEY = ''

traderbagel

from datetime import datetime

ts = 1597809600
dt = datetime.fromtimestamp(ts)

# current date and time
now = datetime.now()
ts = datetime.timestamp(now)

traderbagel

// run in chrome console
(function(){
    $("#side").remove();
    $("#comment_title, #comment_list, #comment_bar, #comment_form, .announce, #ad_cen, #ad_bot").remove();
    $(".nav_top_2011, #header, #navigator").remove();
    $(".p4course_target, .comment-box, .recommend-box, #csdn-toolbar, #tool-box").remove();
    $("aside").remove();
    $(".tool-box").remove();
    $("#toolBarBox").remove();
    $("main").css('display','content');