Plutonic Rainbows

Flagging Extremist Content

February 16, 2018

Great article from ASI Data Science on Binary Classification and ROC Curves.

It is well known that online propaganda from terrorist organisations plays a key part in radicalisation in Europe and the UK. In collaboration with the UK Home Office, we recently developed and tested an AI algorithm designed to detect such propaganda on the web.

Following media coverage of the classifier (see, for example, BBC News and The Guardian), there has been much talk of how it works and its performance. In this post, without exposing the inner workings of the algorithm, we'll do our best to outline the general approach we took to design the classifier. We also specify precisely the metrics used and the performance achieved by the classifier.

Counting Things

February 13, 2018

This (fairly) simple few lines calculates the days between two dates - in this case, the 4th of July 2020. That's 888 days as of February 13th 2018.

from datetime import *

today = date.today()
future = date(2020,07,20)

diff = future - today

print "There are %s days left." % diff.days

Loan Calculator

February 11, 2018

Using the Functions available for Maths, I built a simple loan calculator -including the elif and else statements so that Python can make a decision. I am sure there are much simpler ways of doing this but as I am still learning, it's all I can do right now.

# -*- coding: utf-8 -*-

def amount_to_borrow(loan_request, twelve_months):
    print "Calculating 12 months interest totalling £{0:.2f}.\n".format (twelve_months)
    return loan_request + twelve_months


loan_request = (float(raw_input("How much do you want?\nEnter Amount: ")))

monthly_payments = loan_request / 12

twelve_months = monthly_payments + 15.00 * 12

interest_payments = 15 * 12

total = amount_to_borrow(loan_request, twelve_months)

raw_input("Press Return to get your decision.\n")

credit_limit = 5000

print "The cost of your loan is £{0:.2f}\n".format (total)
print "That's £{0:.2f} in 12 monthly payments".format (monthly_payments)
print "And £{0:.2f} in Interest Payments over 12 months.\n".format (interest_payments)
print "The limit for your account is £{0:.2f}\n".format (credit_limit)

if total < credit_limit:
    print "Your loan is approved.\n"

elif total > credit_limit:
    print "Sorry. You are not approved.\n"

else:
    print "Please come into the branch to discuss it.\n"

Using Functions to do Maths

February 09, 2018

Mathematics isn't really something I'm good at but luckily, Python makes it easy when using functions. I'm also using .format to correctly show decimal places - as well as # -*- coding: utf-8 -*- so that Python can print currency symbols..

# -*- coding: utf-8 -*-
def add(a, b, c):
    print "\nADDING %d + %d + %d" % (a, b, c)
    return a + b + c

price = add(12, 12, 12);print "The price is £{0:.2f}\n".format (price)

def multiply(a, b):
    print "MULTIPLYING %d * %d" % (a, b)
    return a * b

multiply_price = multiply(10, 10);print "The price is £{0:.2f}\n".format (multiply_price)

def subtracting(a, b):
    print "SUBTRACTING %d - %d" % (a, b)
    return a - b

subtract_price = subtracting(100, 50);print "The price is £{0:.2f}\n".format (subtract_price)

def division(a, b):
    print "DIVIDING %d / %d" % (a, b)
    return a / b

division_price = division(90, 2);print "The price is £{0:.2f}\n".format (division_price)

Rewinding

February 07, 2018

This will not sink in. Have to keep looking at it over and over again. I'm just not clever enough, I think. The only way to make it stick is to look at the previous variables etc.

from sys import argv

script, input_file = argv

def print_all(f):
    print f.read()

def rewind(f):
    f.seek(0)

def print_a_line(line_count, f):
    print line_count, f.readline()

current_file = open(input_file)

print "First let's print the whole file:\n"

print_all(current_file)

print "\nNow let's rewind. Just like a tape."

rewind(current_file)

print "Let's print three lines:\n"

current_line = 1
print_a_line(current_line, current_file)

current_line = current_line + 1
print_a_line(current_line, current_file)

current_line = current_line + 1
print_a_line(current_line, current_file)

print "\n"