arseniyturin

import socket
from threading import Thread

def server(host='', port=8000):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
        sock.bind((host, port))
        sock.listen()
        while True:
            client, address = sock.accept()

arseniyturin

# David Beazley async socket server example
# Loops very similar to a 'regular' threaded socket server
# Except we create an event loop and use async/await syntax

import asyncio
import socket

loop = asyncio.get_event_loop()

async def server(address):

arseniyturin

'''
Basic Python Threaded TCP Server
--------------------------------
socketserver.TCPServer requires only two things:
 - Address (host, port)
 - Handler class to process requests
   Must be derived from `BaseRequestHandler` or `StreamRequestHandler`
'''

from socketserver import TCPServer

arseniyturin

def handshake(frame, client):
    headers = http_message.decode('utf8').split('\n')
    for header in headers:
        if header.startswith('Sec-WebSocket-Key'):
            key = header.replace('Sec-WebSocket-Key:', '').strip()
            accept_key = generate_accept_key(key)
            response = (
                "HTTP/1.1 101 Switching Protocols\r\n"
                "Upgrade: websocket\r\n"
                "Connection: Upgrade\r\n"

arseniyturin

from hashlib import sha1
from base64 import b64encode

def generate_accept_key(key):
    GUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
    sha1_hash = sha1((key + GUID).encode()).digest()
    return b64encode(sha1_hash).decode()

arseniyturin

# simplest
import socket
from threading import Thread

def response(client, address):
	print(f'Client connected from: {address}')
	while True:
	  # receiving message
		message = client.recv(1024)
		if not message:

arseniyturin

'''
100 coins / 99 fair + 1 unfair (both heads)
pick one
flip 10 times = 10 heads
what is the probability that this coin is unfair?

           P(A) * P(B|A)
P(A|B) = ----------------
               P(B)
               

arseniyturin

'''
Question: You're travelling to Seattle and you've asked 3 of your friends independently if it will rain,
3 of them said it will. Each friend has 2/3 chances of being right. Should you bring an umbrella?

Assume chance of rain is 25%

                 P(rain) * P(yes | rain)
P(rain | yes) = ------------------------
                        P(yes)

arseniyturin

'''
    
            P(A) * (B|A)
  P(A|B) = -------------- - Bayes Probability
                P(B)   

  Cookie Problem that can be solved with Bayes Probability:
  
  You are given two jars of cookies, jar 1 has 30 vanilla and 10 chocolate cookies,
  jar 2 has 20 vanilla and 20 chocolate cookies.

arseniyturin

"""
Table 'Products' contains different products, their categories and prices.
We want to select top n products per each category rated by their price
SOLUTION: Window function RANK()

1. TABLE 'Products'
┌───────────┬────────────┬───────┐
│  product  │  category  │ price │
├───────────┼────────────┼───────┤
│ product_A │ category_A │ 55    │