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-- Create a group
CREATE ROLE readaccess;

-- Grant access to existing tables
GRANT USAGE ON SCHEMA public TO readaccess;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readaccess;

-- Grant access to future tables
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO readaccess;

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PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

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import pandas as pd
import numpy as np
import re

# ================================================
class option_parser:
    def __init__(self, symbol, response):
        self.symbol = symbol
        self.response = response
    # ------------------------------------------------

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#Spider Websites with Wget – 20 Practical Examples

Wget is extremely powerful, but like with most other command line programs, the plethora of options it supports can be intimidating to new users. Thus what we have here are a collection of wget commands that you can use to accomplish common tasks from downloading single files to mirroring entire websites. It will help if you can read through the wget manual but for the busy souls, these commands are ready to execute.

1. Download a single file from the Internet
wget http://example.com/file.iso

2. Download a file but save it locally under a different name
wget ‐‐output-document=filename.html example.com

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Pub/Sub pattern with PostgreSQL's LISTEN/NOTIFY command

This is a simple chat-like program using pub-sub pattern, backed by PostgreSQL's LISTEN/NOTIFY command.

Publish

publish message to foo channel from user nickname.

$ python pub.py foo nickname
PUBLISH to channel #foo

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# coding=UTF-8
from __future__ import division
import re

# This is a naive text summarization algorithm
# Created by Shlomi Babluki
# April, 2013


class SummaryTool(object):

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from PIL import Image
from PIL.ExifTags import TAGS, GPSTAGS

def get_exif_data(image):
    """Returns a dictionary from the exif data of an PIL Image item. Also converts the GPS Tags"""
    exif_data = {}
    info = image._getexif()
    if info:
        for tag, value in info.items():
            decoded = TAGS.get(tag, tag)

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#!/usr/bin/python

import sys
import os, shutil
import subprocess
import os.path
from datetime import datetime

######################## Functions #########################

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#!/usr/bin/python
import ftplib
session = ftplib.FTP('example.com','username','password')
file = open('cup.mp4','rb')                  # file to send
session.storbinary('STOR '+'cup.mp4', file)     # send the file
file.close()                                    # close file and FTP
session.quit()

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#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: ai ts=4 sts=4 et sw=4


"""
    Tools to extract feed links, test if they are valid and parse them 
    with feedparser, returning content or a proper error.
"""