Acodemics

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Maze Solving with A* In Python

There was a new challenge at work to create a program that can solve 2D ascii mazes, for this challenge I implemented the A* search algorithm, this is a very fast algorithm that uses heuristics to determine whether or not a path is viable. It is very useful for something such as path finding in computer games as there may be different routes available but some routes are preferable to others.

#!/bin/python2.6

import sys
from math import sqrt

class Tile:

    def __init__(self, char, x, y):
        self.char = char
        self.g = 0
        self.h = 0
        self.x = x
        self.y = y
        self.parent = None
        self.setReachable()

    def setReachable(self):
        self.reachable = True
        if self.char in ['-', '+', '|']:
            self.reachable = False

    def move_cost(self, other):
        if other.reachable:
            return 10
        else:
            return 1000

class AStar:

    def __init__(self, maze):
        self.maze = maze

    def getAdjacent(self, cell):
        mazeWidth = len(self.maze[0])
        mazeHeight = len(self.maze)
        ret = []
        if cell.y > 0:
            ret.append(self.getTileAtCoords(cell.x, cell.y - 1))
        if cell.x < mazeWidth - 1:
            ret.append(self.getTileAtCoords(cell.x + 1, cell.y))
        if cell.y < mazeHeight - 1:
            ret.append(self.getTileAtCoords(cell.x, cell.y + 1))
        if cell.x > 0:
            ret.append(self.getTileAtCoords(cell.x - 1, cell.y))
        return ret

    def heuristic(self, cell):
        return sqrt((self.end.x - cell.x)**2 + (self.end.y - cell.y)**2)

    def constructPath(self, current):
        path = []
        while current.parent:
            path.append(current)
            current = current.parent
        path.append(current)
        return path[::-1]

    def getTileAtCoords(self, x, y):
        try:
            return self.maze[y][x]
        except KeyError as e:
            print "Could not find tile at position x: {0} y: {1}".format(x, y)

    def search(self, current, end):
        self.end = end
        openset = set()
        closedset = set()
        openset.add(current)
        while len(openset):
            current = min(openset, key=lambda o:o.g + o.h)
            if current == end:
                return self.constructPath(current)
            openset.remove(current)
            closedset.add(current)
            for node in self.getAdjacent(current):
                if node in closedset:
                    continue
                if node in openset:
                    new_g = current.g + current.move_cost(node)
                    if node.g > new_g:
                        node.g = new_g
                        node.parent = current
                else:
                    node.g = current.g + current.move_cost(node)
                    node.h = self.heuristic(node)
                    node.parent = current
                    openset.add(node)

def getMaze():
    maze = []
    for i ,line in enumerate(sys.stdin):
        line = list (line.rstrip("\r\n"))
        row = []
        for j in range(len(line)):
            row.append(Tile(line[j], j, i))
        maze.append(row)
    return maze

def fillPath(maze):
    aStar = AStar(maze)
    for tile in aStar.search(maze[1][0], maze[-2][-1]):
        maze[tile.y][tile.x].char = "#"

def printMaze(maze):
    for row in maze:
        for tile in row:
            sys.stdout.write(tile.char)
        print

if __name__ == "__main__":

    maze = getMaze()
    fillPath(maze)
    printMaze(maze)

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#!/bin/python2.6

import sys

from math import sqrt

class Tile:

def __init__(self, char, x, y):

self.char = char

self.g = 0

self.h = 0

self.x = x

self.y = y

self.parent = None

self.setReachable()

def setReachable(self):

self.reachable = True

if self.char in ['-', '+', '|']:

self.reachable = False

def move_cost(self, other):

if other.reachable:

return 10

else:

return 1000

class AStar:

def __init__(self, maze):

self.maze = maze

def getAdjacent(self, cell):

mazeWidth = len(self.maze[0])

mazeHeight = len(self.maze)

ret = []

if cell.y > 0:

ret.append(self.getTileAtCoords(cell.x, cell.y - 1))

if cell.x < mazeWidth - 1:

ret.append(self.getTileAtCoords(cell.x + 1, cell.y))

if cell.y < mazeHeight - 1:

ret.append(self.getTileAtCoords(cell.x, cell.y + 1))

if cell.x > 0:

ret.append(self.getTileAtCoords(cell.x - 1, cell.y))

return ret

def heuristic(self, cell):

return sqrt((self.end.x - cell.x)**2 + (self.end.y - cell.y)**2)

def constructPath(self, current):

path = []

while current.parent:

path.append(current)

current = current.parent

path.append(current)

return path[::-1]

def getTileAtCoords(self, x, y):

try:

return self.maze[y][x]

except KeyError as e:

print "Could not find tile at position x: {0} y: {1}".format(x, y)

def search(self, current, end):

self.end = end

openset = set()

closedset = set()

openset.add(current)

while len(openset):

current = min(openset, key=lambda o:o.g + o.h)

if current == end:

return self.constructPath(current)

openset.remove(current)

closedset.add(current)

for node in self.getAdjacent(current):

if node in closedset:

continue

if node in openset:

new_g = current.g + current.move_cost(node)

if node.g > new_g:

node.g = new_g

node.parent = current

else:

node.g = current.g + current.move_cost(node)

node.h = self.heuristic(node)

node.parent = current

openset.add(node)

def getMaze():

maze = []

for i ,line in enumerate(sys.stdin):

line = list (line.rstrip("\r\n"))

row = []

for j in range(len(line)):

row.append(Tile(line[j], j, i))

maze.append(row)

return maze

def fillPath(maze):

aStar = AStar(maze)

for tile in aStar.search(maze[1][0], maze[-2][-1]):

maze[tile.y][tile.x].char = "#"

def printMaze(maze):

for row in maze:

for tile in row:

sys.stdout.write(tile.char)

if __name__ == "__main__":

maze = getMaze()

fillPath(maze)

printMaze(maze)

The mazes look like this –

+--+--+--+--+--+--+--+--+--+--+
      |        |        |     |
+  +  +  +--+  +--+--+  +  +--+
|  |     |  |  |     |  |     |
+  +--+--+  +  +  +  +  +--+  +
|        |     |  |        |  |
+  +--+--+--+--+--+  +--+--+  +
|        |  |     |  |     |  |
+--+--+  +  +  +  +  +  +  +  +
|        |     |  |  |  |     |
+  +--+--+--+--+  +  +  +--+  +
|  |                 |     |  |
+  +--+--+--+--+  +--+  +  +  +
|           |     |     |  |  |
+--+--+--+  +  +--+--+--+  +  +
|           |  |  |        |  |
+  +--+  +--+  +  +  +--+--+  +
|     |           |  |     |  |
+--+  +--+--+--+--+  +  +  +  +
|                    |  |      
+--+--+--+--+--+--+--+--+--+--+

+--+--+--+--+--+--+--+--+--+--+

| | | |

+ + + +--+ +--+--+ + +--+

| | | | | | | |

+ +--+--+ + + + + +--+ +

| | | | | |

+ +--+--+--+--+--+ +--+--+ +

| | | | | | |

+--+--+ + + + + + + + +

| | | | | | |

+ +--+--+--+--+ + + +--+ +

| | | | |

+ +--+--+--+--+ +--+ + + +

| | | | | |

+--+--+--+ + +--+--+--+ + +

| | | | | |

+ +--+ +--+ + + +--+--+ +

| | | | | |

+--+ +--+--+--+--+ + + + +

| | |

+--+--+--+--+--+--+--+--+--+--+

Here is a larger one –

+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
            |  |                 |     |                    |     |     |  |
+--+--+--+  +  +  +--+--+  +--+  +--+  +--+  +--+--+--+  +  +  +--+  +  +  +
|              |     |     |  |  |     |     |        |  |  |  |     |  |  |
+  +--+--+--+--+--+  +--+--+  +  +  +--+  +--+  +--+  +--+  +  +  +--+  +  +
|  |              |     |     |  |  |  |     |  |  |     |     |  |     |  |
+  +--+--+  +--+  +--+  +  +--+  +  +  +  +  +  +  +--+  +--+  +  +  +--+  +
|        |  |     |     |        |  |     |  |     |  |     |  |  |     |  |
+--+--+  +  +  +--+  +--+  +--+  +  +--+--+  +--+--+  +--+  +  +  +--+  +  +
|        |  |     |     |  |     |     |     |     |  |        |  |  |  |  |
+  +--+--+  +--+  +--+  +  +--+--+--+  +  +--+  +  +  +--+  +--+  +  +  +  +
|  |        |  |     |  |                 |     |  |     |  |     |  |     |
+  +  +--+--+  +--+  +  +--+--+--+--+  +--+  +--+  +--+  +  +  +--+  +--+--+
|     |     |  |  |     |           |     |     |        |  |  |        |  |
+  +--+  +  +  +  +--+--+  +--+--+  +--+  +--+--+--+  +--+--+  +  +--+  +  +
|  |     |     |        |  |     |        |  |     |  |     |  |  |        |
+  +  +--+--+--+  +--+  +  +--+  +--+--+--+  +  +  +  +  +  +  +  +  +--+--+
|     |  |           |  |     |  |        |     |        |  |     |        |
+--+--+  +  +--+--+--+  +--+  +  +  +  +--+--+  +--+  +--+--+  +--+--+--+  +
|        |  |        |     |  |  |  |        |  |     |     |     |        |
+  +--+  +  +  +--+  +--+  +  +  +  +--+  +--+  +  +--+  +  +--+  +  +--+--+
|  |  |  |        |     |  |     |     |        |     |  |     |  |        |
+  +  +  +--+  +  +--+  +--+  +--+--+  +--+--+--+--+  +  +--+  +  +--+--+  +
|  |  |     |  |  |  |        |     |  |              |     |  |  |  |     |
+  +  +--+  +  +  +  +--+--+--+--+  +  +--+--+  +--+--+  +  +  +  +  +  +--+
|     |  |  |  |  |        |     |     |        |     |  |  |  |  |        |
+--+--+  +  +  +  +--+--+  +  +  +  +--+  +--+  +  +  +  +--+  +  +--+--+  +
|     |  |     |        |  |  |  |  |        |  |  |  |     |     |     |  |
+  +  +  +--+--+--+--+  +  +  +  +  +  +--+  +--+  +  +--+  +--+--+--+  +  +
|  |  |        |           |  |     |     |        |     |        |     |  |
+  +  +  +--+  +--+--+  +  +  +--+--+--+  +--+--+--+--+--+  +--+--+  +--+--+
|  |  |     |           |              |     |           |  |     |  |     |
+  +  +--+  +--+--+  +--+--+--+--+--+  +--+  +  +--+--+  +  +  +  +  +  +  +
|  |     |  |     |  |        |        |     |  |        |  |  |     |  |  |
+  +--+  +  +  +  +  +--+--+  +  +--+--+  +--+  +  +--+--+  +  +  +--+  +  +
|  |  |     |  |  |        |     |     |  |     |  |     |  |  |  |     |  |
+  +  +--+--+  +--+--+  +--+--+--+  +  +  +  +  +  +  +  +  +--+  +  +--+  +
|  |        |        |     |  |     |     |  |  |     |     |     |  |     |
+  +--+--+  +  +--+  +  +  +  +  +--+--+--+  +  +--+--+--+--+  +--+  +  +--+
|           |  |     |  |     |              |                 |     |     |
+--+--+--+--+  +  +--+--+--+  +--+--+--+  +--+--+--+--+--+--+--+  +--+--+  +
|  |        |  |              |           |     |     |        |  |     |  |
+  +  +--+  +  +--+--+--+--+--+--+  +--+--+  +  +  +  +  +--+--+  +  +--+  +
|     |     |  |        |  |                 |  |  |              |        |
+--+--+--+  +  +  +--+  +  +  +  +  +--+  +--+  +  +--+--+--+--+  +  +--+--+
|        |        |     |     |  |  |     |  |  |     |        |  |        |
+  +--+  +--+--+--+  +--+--+--+--+  +  +--+  +  +--+  +--+--+  +--+--+--+  +
|     |        |     |  |        |  |     |     |     |           |        |
+--+  +--+  +  +  +--+  +  +--+  +--+--+  +  +--+  +--+  +--+--+  +  +--+--+
|     |     |     |        |              |              |        |         
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

| | | | | | | |

+--+--+--+ + + +--+--+ +--+ +--+ +--+ +--+--+--+ + + +--+ + + +

| | | | | | | | | | | | | | |

+ +--+--+--+--+--+ +--+--+ + + +--+ +--+ +--+ +--+ + + +--+ + +

| | | | | | | | | | | | | | | |

+ +--+--+ +--+ +--+ + +--+ + + + + + + +--+ +--+ + + +--+ +

| | | | | | | | | | | | | | | |

+--+--+ + + +--+ +--+ +--+ + +--+--+ +--+--+ +--+ + + +--+ + +

| | | | | | | | | | | | | | | |

+ +--+--+ +--+ +--+ + +--+--+--+ + +--+ + + +--+ +--+ + + + +

| | | | | | | | | | | | | |

+ + +--+--+ +--+ + +--+--+--+--+ +--+ +--+ +--+ + + +--+ +--+--+

| | | | | | | | | | | | | |

+ +--+ + + + +--+--+ +--+--+ +--+ +--+--+--+ +--+--+ + +--+ + +

| | | | | | | | | | | | | | |

+ + +--+--+--+ +--+ + +--+ +--+--+--+ + + + + + + + + +--+--+

| | | | | | | | | | | | |

+--+--+ + +--+--+--+ +--+ + + + +--+--+ +--+ +--+--+ +--+--+--+ +

| | | | | | | | | | | | | |

+ +--+ + + +--+ +--+ + + + +--+ +--+ + +--+ + +--+ + +--+--+

| | | | | | | | | | | | | | |

+ + + +--+ + +--+ +--+ +--+--+ +--+--+--+--+ + +--+ + +--+--+ +

| | | | | | | | | | | | | | | |

+ + +--+ + + + +--+--+--+--+ + +--+--+ +--+--+ + + + + + +--+

| | | | | | | | | | | | | | | |

+--+--+ + + + +--+--+ + + + +--+ +--+ + + + +--+ + +--+--+ +

| | | | | | | | | | | | | | | | |

+ + + +--+--+--+--+ + + + + + +--+ +--+ + +--+ +--+--+--+ + +

| | | | | | | | | | | | |

+ + + +--+ +--+--+ + + +--+--+--+ +--+--+--+--+--+ +--+--+ +--+--+

| | | | | | | | | | | |

+ + +--+ +--+--+ +--+--+--+--+--+ +--+ + +--+--+ + + + + + + +

| | | | | | | | | | | | | | | |

+ +--+ + + + + +--+--+ + +--+--+ +--+ + +--+--+ + + +--+ + +

| | | | | | | | | | | | | | | | | |

+ + +--+--+ +--+--+ +--+--+--+ + + + + + + + + +--+ + +--+ +

| | | | | | | | | | | | | | |

+ +--+--+ + +--+ + + + + +--+--+--+ + +--+--+--+--+ +--+ + +--+

| | | | | | | | | |

+--+--+--+--+ + +--+--+--+ +--+--+--+ +--+--+--+--+--+--+--+ +--+--+ +

| | | | | | | | | | | |

+ + +--+ + +--+--+--+--+--+--+ +--+--+ + + + + +--+--+ + +--+ +

| | | | | | | | | | |

+--+--+--+ + + +--+ + + + + +--+ +--+ + +--+--+--+--+ + +--+--+

| | | | | | | | | | | | | |

+ +--+ +--+--+--+ +--+--+--+--+ + +--+ + +--+ +--+--+ +--+--+--+ +

| | | | | | | | | | | |

+--+ +--+ + + +--+ + +--+ +--+--+ + +--+ +--+ +--+--+ + +--+--+

| | | | | | | |

+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

Save the mazes into a file and pipe them into the program.

Java Create Relative Date

October 23, 2014 / Jack Concanon / 0 Comments

This is a small part of an Android application I’m working on; couldn’t find a simple Java relative date function so here’s one I made.

public static String getRelativeDate(long timestamp) {
        Calendar secondDate = Calendar.getInstance();
        secondDate.setTimeInMillis(timestamp * 1000);
        Calendar currentDate = Calendar.getInstance();

        int yearDifference = secondDate.get(Calendar.YEAR) - currentDate.get(Calendar.YEAR);
        int monthDifference = secondDate.get(Calendar.MONTH) - currentDate.get(Calendar.MONTH);
        int dayDifference = secondDate.get(Calendar.DAY_OF_MONTH) - currentDate.get(Calendar.DAY_OF_MONTH);
        int hourDifference = secondDate.get(Calendar.HOUR) - currentDate.get(Calendar.HOUR);
        int minuteDifference = secondDate.get(Calendar.MINUTE) - currentDate.get(Calendar.MINUTE);
        int secondDifference = secondDate.get(Calendar.SECOND) - currentDate.get(Calendar.SECOND);

        if(yearDifference >= 1 || yearDifference < -1) {
            return createDifference("year", yearDifference);
        } else if(monthDifference >= 1 || monthDifference < -1) {
            return createDifference("month", monthDifference);
        } else if(dayDifference >= 1 || dayDifference < -1) {
            return createDifference("day", dayDifference);
        } else if(hourDifference >= 1 || hourDifference < -1) {
            return createDifference("hour", hourDifference);
        } else if(minuteDifference >= 1 || minuteDifference < -1) {
            return createDifference("minute", minuteDifference);
        } else if(secondDifference >= 1 || secondDifference < -1) {
            return createDifference("second", secondDifference);
        } else {
            return "Now";
        }
    }

    private static String createDifference(String part, int difference) {
        String s = (Math.abs(difference) > 1) ? "s" : "";
        if(difference >= 1) {
            return String.format("In %d %s%s", difference, part, s);
        } else {
            return String.format("%d %s%s ago", Math.abs(difference), part, s);
        }
    }

public static String getRelativeDate(long timestamp) {

Calendar secondDate = Calendar.getInstance();

secondDate.setTimeInMillis(timestamp * 1000);

Calendar currentDate = Calendar.getInstance();

int yearDifference = secondDate.get(Calendar.YEAR) - currentDate.get(Calendar.YEAR);

int monthDifference = secondDate.get(Calendar.MONTH) - currentDate.get(Calendar.MONTH);

int dayDifference = secondDate.get(Calendar.DAY_OF_MONTH) - currentDate.get(Calendar.DAY_OF_MONTH);

int hourDifference = secondDate.get(Calendar.HOUR) - currentDate.get(Calendar.HOUR);

int minuteDifference = secondDate.get(Calendar.MINUTE) - currentDate.get(Calendar.MINUTE);

int secondDifference = secondDate.get(Calendar.SECOND) - currentDate.get(Calendar.SECOND);

if(yearDifference >= 1 || yearDifference < -1) {

return createDifference("year", yearDifference);

} else if(monthDifference >= 1 || monthDifference < -1) {

return createDifference("month", monthDifference);

} else if(dayDifference >= 1 || dayDifference < -1) {

return createDifference("day", dayDifference);

} else if(hourDifference >= 1 || hourDifference < -1) {

return createDifference("hour", hourDifference);

} else if(minuteDifference >= 1 || minuteDifference < -1) {

return createDifference("minute", minuteDifference);

} else if(secondDifference >= 1 || secondDifference < -1) {

return createDifference("second", secondDifference);

} else {

return "Now";

}

private static String createDifference(String part, int difference) {

String s = (Math.abs(difference) > 1) ? "s" : "";

if(difference >= 1) {

return String.format("In %d %s%s", difference, part, s);

} else {

return String.format("%d %s%s ago", Math.abs(difference), part, s);

}

Finished: Batman Arkham Origins

October 4, 2014 / Jack Concanon / 0 Comments

An interesting third part to the Batman Arkham series, unfortunately it lacks the charm and interest of the first two games. It would have been more interesting to see the rise and origins of the various baddies of the series rather than just the Joker.

The combat is excellent as you would expect from a Batman game, the ability to flow together combos is something that never gets old and there is a healthy array of gadgets to help you.

The game has plenty of content and kept me going for around 30 hours. Unfortunately there were a couple of bugs that impacted the gameplay such as enemies becoming far too intimate with walls and various prompts not being displayed when they should have been.

The third installment of the Batman Arkham series is an intriguing addition to the franchise. While it may not have captured the same charm and interest as the first two games, it still offers an enjoyable experience for fans.

The combat mechanics in the game remain excellent, as expected from a Batman title. The seamless flow of combos and the wide selection of gadgets at your disposal contribute to an immersive and satisfying combat experience.

With a generous amount of content, the game provides around 30 hours of gameplay, offering a substantial experience for players. However, it is unfortunate that some bugs impacted the overall gameplay. Issues such as enemies getting too close to walls and prompts failing to display when necessary can disrupt the immersion and enjoyment of the game, as there are many games you can enjoy such as casino games from the highway casino online.

Despite these flaws, the game still offers a solid experience for fans of the series. The engaging combat, rich content, and the opportunity to step into the shoes of Batman make it worth exploring.

Overall it’s a solid game in an excellent series.

Finished: Dawn of War 2: Chaos Rising

September 28, 2014 / Jack Concanon / 0 Comments

I actually preferred the base game over chaos rising, the Tyranids provide a real exciting and credible threat whereas the Chaos Space Marines come off as cartoonish and arrogant.

The overall length of the game was short and the character progression stops too soon, meaning that your main squads reach maximum level half way through the game!

The boss fights are basically bullet sponges with some annoying area of effect attacks.

Over all – stick to Dawn of War 2.

September 17, 2014

Python Port Tunneler

September 3, 2014 / Jack Concanon / 0 Comments

I needed to be able to remote debug a process that was hidden behind a middle server so I made a Python script that can create a ‘middle man’ port to allow for this.

Basically if you have server-B which is only accessible through server-A then the script creates a port on server-A that links to the desired remote debug port on server-B and provides a new port to forward all traffic through.

It’s probably possible to do this all with some cryptic SSH command but this works better for me, plus I got to do some more Python. It uses the gevent library, which is an extremely fast and efficient socket library and can be downloaded from any good repository.

The usage is quite simple –

python Tunnel.py --remoteHost hiddenMachine --remotePort 8888 --localPort 
9999 --localHost visibleServer

1 2	python Tunnel.py --remoteHost hiddenMachine --remotePort 8888 --localPort 9999 --localHost visibleServer

The code –

#!/usr/bin/python

import optparse
import signal
import sys
import logging
import gevent
from gevent.server import StreamServer
from gevent.socket import create_connection, gethostbyname

DEBUG = False

class Logger:
    def __init__(self, name, stdout):
        self.logger = logging.getLogger('')
        self.logger.setLevel(logging.DEBUG)
        if stdout:
            the_format = "%(asctime)s\t%(levelname)s\t%(message)s"
            logging.basicConfig(format=the_format)

    def get_logger(self):
        return self.logger

class PortForwarder(StreamServer):

    def __init__(self, source, dest, logger, **kwargs):
        StreamServer.__init__(self, source, **kwargs)
        self.source = source
        self.dest = dest
        self.logger = logger
        self.closed = False
        self.output_socket = None

    def handle(self, source, address):
        self.logger.info('{0}:{1} accepted'.format(address[0], address[1]))
        try:
            if not self.output_socket:
                self.output_socket = create_connection(self.dest)
            gevent.spawn(join, source, self.output_socket, self.logger)
            gevent.spawn(join, self.output_socket, source, self.logger)
        except IOError as ex:
            self.logger.info('{0}:{1} failed to connect to {2}:{3} - {4}'.format(address[0], address[1], self.dest[0], self.dest[1], ex))
            return

    def close(self):
        if self.closed:
            self.logger.info('Multiple exit signals received - aborting.')
            sys.exit(0)
        else:
            self.logger.info('Closing listener socket')
            #StreamServer.close(self)
            
def join(input_socket, output_socket, logger):
    try:
        if DEBUG:
            input_destination = "{0}:{1}".format(input_socket.getsockname()[0], input_socket.getsockname()[1])
            output_destination = "{0}:{1}".format(output_socket.getsockname()[0], output_socket.getsockname()[1])
            logger.info("{0} -> {1}".format(input_destination, output_destination))
        while True:
            data = input_socket.recv(1024)
            if not data:
                break
            output_socket.sendall(data)
    except Exception as e:
        logger.info("Exception encounted: {0}".format(e))
    finally:
        input_socket.close()
        output_socket.close()

def get_opts():
    p = optparse.OptionParser()
    p.add_option('--remoteHost', default=None, dest='remote_host', help='Remote host name')
    p.add_option('--remotePort', default=None, dest='remote_port', help='Remote port')
    p.add_option('--localHost', default=None, dest='local_host', help='Local host name')
    p.add_option('--localPort', default=None, dest='local_port', help='Local port')
    (opts, args) = p.parse_args()
    if opts.remote_port is None or opts.local_port is None:
        p.print_help()
        sys.exit(1)
    return opts


if __name__ == "__main__":

    opts = get_opts()
    logger = Logger('Tunnel', True)
    
    source = (opts.local_host, int(opts.local_port))
    dest = (opts.remote_host, int(opts.remote_port))

    server = PortForwarder(source, dest, logger.get_logger())
    logger.get_logger().info("Starting port forwarder {0}:{1} -> {2}:{3}".format(source[0], source[1], dest[0], dest[1]))
    gevent.signal(signal.SIGTERM, server.close)
    gevent.signal(signal.SIGINT, server.close)

    try:
        gevent.joinall([
            server.serve_forever()
        ])
    except KeyboardInterrupt as e:
        logger.get_logger().info("Shutting down.")
    except Exception as e:
        logger.get_logger().info("Unknown exception: '{0}'".format(e))
    finally:
        server.stop()

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#!/usr/bin/python

import optparse

import signal

import sys

import logging

import gevent

from gevent.server import StreamServer

from gevent.socket import create_connection, gethostbyname

DEBUG = False

class Logger:

def __init__(self, name, stdout):

self.logger = logging.getLogger('')

self.logger.setLevel(logging.DEBUG)

if stdout:

the_format = "%(asctime)s\t%(levelname)s\t%(message)s"

logging.basicConfig(format=the_format)

def get_logger(self):

return self.logger

class PortForwarder(StreamServer):

def __init__(self, source, dest, logger, **kwargs):

StreamServer.__init__(self, source, **kwargs)

self.source = source

self.dest = dest

self.logger = logger

self.closed = False

self.output_socket = None

def handle(self, source, address):

self.logger.info('{0}:{1} accepted'.format(address[0], address[1]))

try:

if not self.output_socket:

self.output_socket = create_connection(self.dest)

gevent.spawn(join, source, self.output_socket, self.logger)

gevent.spawn(join, self.output_socket, source, self.logger)

except IOError as ex:

self.logger.info('{0}:{1} failed to connect to {2}:{3} - {4}'.format(address[0], address[1], self.dest[0], self.dest[1], ex))

return

def close(self):

if self.closed:

self.logger.info('Multiple exit signals received - aborting.')

sys.exit(0)

else:

self.logger.info('Closing listener socket')

#StreamServer.close(self)

def join(input_socket, output_socket, logger):

try:

if DEBUG:

input_destination = "{0}:{1}".format(input_socket.getsockname()[0], input_socket.getsockname()[1])

output_destination = "{0}:{1}".format(output_socket.getsockname()[0], output_socket.getsockname()[1])

logger.info("{0} -> {1}".format(input_destination, output_destination))

while True:

data = input_socket.recv(1024)

if not data:

break

output_socket.sendall(data)

except Exception as e:

logger.info("Exception encounted: {0}".format(e))

finally:

input_socket.close()

output_socket.close()

def get_opts():

p = optparse.OptionParser()

p.add_option('--remoteHost', default=None, dest='remote_host', help='Remote host name')

p.add_option('--remotePort', default=None, dest='remote_port', help='Remote port')

p.add_option('--localHost', default=None, dest='local_host', help='Local host name')

p.add_option('--localPort', default=None, dest='local_port', help='Local port')

(opts, args) = p.parse_args()

if opts.remote_port is None or opts.local_port is None:

p.print_help()

sys.exit(1)

return opts

if __name__ == "__main__":

opts = get_opts()

logger = Logger('Tunnel', True)

source = (opts.local_host, int(opts.local_port))

dest = (opts.remote_host, int(opts.remote_port))

server = PortForwarder(source, dest, logger.get_logger())

logger.get_logger().info("Starting port forwarder {0}:{1} -> {2}:{3}".format(source[0], source[1], dest[0], dest[1]))

gevent.signal(signal.SIGTERM, server.close)

gevent.signal(signal.SIGINT, server.close)

try:

gevent.joinall([

server.serve_forever()

])

except KeyboardInterrupt as e:

logger.get_logger().info("Shutting down.")

except Exception as e:

logger.get_logger().info("Unknown exception: '{0}'".format(e))

finally:

server.stop()

Image Recognition Tool

August 13, 2014 / Jack Concanon / 0 Comments

As I’ve recently got quite into machine learning tools I’ve written a small GUI based tool that uses the PyBrains library to ‘learn’ a common theme from a folder of training data. To test new images, drag and drop them onto the tool to get a percentage of similarity to the test data.

The tool is written using Python, PyBrains, Glade2 and PyGTK so you need those libraries available.

The tool can be downloaded here – image_recognition_tool

August 4, 2014

A presentation I made for work that is an introduction to machine learning. Notes included with power point slides. Machine Learning

Image Recognition with PyBrains

June 20, 2014 / Jack Concanon / 0 Comments

After recently completing the Machine Learning course from Stanford University on Coursera I’ve been preparing to give a small introduction to machine learning at work. Part of that is showing some demos of machine learning tools.

I made a character recognition neural network using the PyBrains Python library, it’s a great library and very fast but the documentation is very poor and examples are hard to come across. With enough digging I managed to put together something very simple and short.

In this example it reads in small PNG files of letters, extracts all of the pixel values and creates a 1D array of the values, this is used to train the neural network through back propagation. I test the network on one of the inputs. Each input is classified with a number in the addSample function, this takes the flattened array and a number (unfortunately it does not take a string as a classification). If you run the application you will see that, for example when using b.png as a test, it will return a value close to 2.

You can download the images I used here – Machine Learning Training Characters.

#!/usr/bin/python

from pybrain.datasets.supervised import SupervisedDataSet 
from pybrain.tools.shortcuts import buildNetwork
from pybrain.supervised.trainers import BackpropTrainer
import cv2

def loadImage(path):
    im = cv2.imread(path)
    return flatten(im)

def flatten(x):
    result = []
    for el in x:
        if hasattr(el, "__iter__") and not isinstance(el, basestring):
            result.extend(flatten(el))
        else:
            result.append(el)
    return result

if __name__ == "__main__":

    t = loadImage('a.png')

    net = buildNetwork(len(t), len(t), 1)
    ds = SupervisedDataSet(len(t), 1)
    ds.addSample(loadImage('a.png'),(1,))
    ds.addSample(loadImage('b.png'),(2,))
    ds.addSample(loadImage('c.png'),(3,))
    ds.addSample(loadImage('d.png'),(4,))

    trainer = BackpropTrainer(net, ds)
    error = 10
    iteration = 0
    while error > 0.001: 
        error = trainer.train()
        iteration += 1
        print "Iteration: {0} Error {1}".format(iteration, error)

    print "\nResult: ", net.activate(loadImage('b.png'))

#!/usr/bin/python

from pybrain.datasets.supervised import SupervisedDataSet

from pybrain.tools.shortcuts import buildNetwork

from pybrain.supervised.trainers import BackpropTrainer

import cv2

def loadImage(path):

im = cv2.imread(path)

return flatten(im)

def flatten(x):

result = []

for el in x:

if hasattr(el, "__iter__") and not isinstance(el, basestring):

result.extend(flatten(el))

else:

result.append(el)

return result

if __name__ == "__main__":

t = loadImage('a.png')

net = buildNetwork(len(t), len(t), 1)

ds = SupervisedDataSet(len(t), 1)

ds.addSample(loadImage('a.png'),(1,))

ds.addSample(loadImage('b.png'),(2,))

ds.addSample(loadImage('c.png'),(3,))

ds.addSample(loadImage('d.png'),(4,))

trainer = BackpropTrainer(net, ds)

error = 10

iteration = 0

while error > 0.001:

error = trainer.train()

iteration += 1

print "Iteration: {0} Error {1}".format(iteration, error)

print "\nResult: ", net.activate(loadImage('b.png'))

Ceaser Cipher Cracker

April 9, 2014 / Jack Concanon / 0 Comments

Another programming challenge from work to solve Ceaser ciphered sentences and return the correct shift value. Automatic solving of the cypher is easy enough but the hard part comes to automatically detecting if the resulting shifted sentence is English. I have posted before about detecting English using ngrams and used a similar process here.

Here is the code which contains the four test cases.

#!/bin/python

class Ngram:

    # Sources
    # https://en.wikipedia.org/wiki/Letter_frequency
    # https://en.wikipedia.org/wiki/Bigram
    # https://en.wikipedia.org/wiki/Trigram

    def __init__(self):
        self.ngrams = ['the', 'and', 'tha', 'ent', 'ing', 'ion', 'tio', 'for',
        'nde', 'has', 'nce', 'edt', 'tis', 'oft', 'sth', 'men', 'th', 
        'he', 'ed', 'of', 'in', 'to', 'er', 'as', 'her', 'ng',
        'of', 'an', 'in', 'ld', 'de', 'ra', 'de', 'se', 'ur', 'ea', 
        'hi', 'or', 'to', 'st', 'nt', 'll', 'ee', 'ss', 'oo', 
        'tt', 'ff', 'rr', 'nn', 'pp', 'cc']
        self.probability = 0.0

    def parse_text(self, text):
        count = 0.0
        self.probability = 0.0
        for ngram in self.ngrams:
            count += text.count(ngram)
        self.probability = (count / len(self.ngrams)) * 100
        return self.probability

    def get_probability(self):
        return self.probability

class CeaserCipher:

    def __init__(self):
        self.ngram = Ngram()
        self.alphabet = list('abcdefghijklmnopqrstuvwxyz')

    def shiftWord(self, text, shift):
        l_word = list(text)
        for i, c in enumerate(l_word):
            if c in self.alphabet:
                p = (self.alphabet.index(c) + shift) % 26
                l_word[i] = self.alphabet[p]
        return "".join(l_word)

    def decrypt(self, text):
        highest_probability = 0
        best_phrase = ''
        best_shift = 0
        for shift in range(-13, 14):
            shifted = self.shiftWord(text.lower(), shift)
            self.ngram.parse_text(shifted)
            if self.ngram.get_probability() > highest_probability:
                highest_probability = self.ngram.get_probability()
                best_phrase = shifted
                best_shift = shift
            #print "{0} : SHIFT - {1} IS ENGLISH? - {2}".format(shifted, shift, self.ngram.parse_text(shifted))
        print "PHRASE: {0}\nSHIFT: {1}\n".format(best_phrase, best_shift)

if __name__ == "__main__":

    phrases = ["BYFFI QILFX", "DRO OKQVO RKC VKXNON", "MCI AIGH IBQCJSF HVS HFIHV HC IBQCJSF HVS ZWS", "GOOD WORK"]
    ceaser = CeaserCipher()

    for phrase in phrases:
        ceaser.decrypt(phrase)

#!/bin/python

class Ngram:

# Sources

# https://en.wikipedia.org/wiki/Letter_frequency

# https://en.wikipedia.org/wiki/Bigram

# https://en.wikipedia.org/wiki/Trigram

def __init__(self):

self.ngrams = ['the', 'and', 'tha', 'ent', 'ing', 'ion', 'tio', 'for',

'nde', 'has', 'nce', 'edt', 'tis', 'oft', 'sth', 'men', 'th',

'he', 'ed', 'of', 'in', 'to', 'er', 'as', 'her', 'ng',

'of', 'an', 'in', 'ld', 'de', 'ra', 'de', 'se', 'ur', 'ea',

'hi', 'or', 'to', 'st', 'nt', 'll', 'ee', 'ss', 'oo',

'tt', 'ff', 'rr', 'nn', 'pp', 'cc']

self.probability = 0.0

def parse_text(self, text):

count = 0.0

self.probability = 0.0

for ngram in self.ngrams:

count += text.count(ngram)

self.probability = (count / len(self.ngrams)) * 100

return self.probability

def get_probability(self):

return self.probability

class CeaserCipher:

def __init__(self):

self.ngram = Ngram()

self.alphabet = list('abcdefghijklmnopqrstuvwxyz')

def shiftWord(self, text, shift):

l_word = list(text)

for i, c in enumerate(l_word):

if c in self.alphabet:

p = (self.alphabet.index(c) + shift) % 26

l_word[i] = self.alphabet[p]

return "".join(l_word)

def decrypt(self, text):

highest_probability = 0

best_phrase = ''

best_shift = 0

for shift in range(-13, 14):

shifted = self.shiftWord(text.lower(), shift)

self.ngram.parse_text(shifted)

if self.ngram.get_probability() > highest_probability:

highest_probability = self.ngram.get_probability()

best_phrase = shifted

best_shift = shift

#print "{0} : SHIFT - {1} IS ENGLISH? - {2}".format(shifted, shift, self.ngram.parse_text(shifted))

print "PHRASE: {0}\nSHIFT: {1}\n".format(best_phrase, best_shift)

if __name__ == "__main__":

phrases = ["BYFFI QILFX", "DRO OKQVO RKC VKXNON", "MCI AIGH IBQCJSF HVS HFIHV HC IBQCJSF HVS ZWS", "GOOD WORK"]

ceaser = CeaserCipher()

for phrase in phrases:

ceaser.decrypt(phrase)

Fitbit Flex Bluetooth Syncing with HTC One X

April 1, 2014 / Jack Concanon / 0 Comments

Finally got Bluetooth syncing from my One X to my Fitbit Flex, here’s how –

First ensure that your phone has at least Android 4.3 or higher, in my case I’m running Cyanogenmod 10.2, then head to this link to sign up for the Fitbit Beta – https://groups.google.com/forum/#%21forum/fitbit-android-sync-beta. Once you sign up to for beta access it may take around ten minutes for this to register with Google, then an update to the Fitbit application will be available on your phone.

After the update ensure that Bluetooth is active and enjoy your wireless syncing!

C# DateTimePicker in PropertyGrid

March 20, 2014 / Jack Concanon / 1 Comment

Property grids are great for quickly giving users an interface for interacting with objects in WPF but customising them is not obvious. Luckily it is possible by extending the UIEditor class to launch custom GUI controls.

In this example I wanted to customise the default DateTime handler of PropertyGrid to include hours, minutes and seconds as unfortunately it only shows the date by default. The following class shows how to extend UIEditor in order to launch a pop-up DateTimePicker when the user selects the item.

using System;
using System.ComponentModel;
using System.Drawing.Design;
using System.Windows.Forms;
using System.Windows.Forms.Design;

namespace Util
{
    public class DateTimePickerEditor : UITypeEditor
    {

        IWindowsFormsEditorService editorService;
        DateTimePicker picker = new DateTimePicker();

        public DateTimePickerEditor()
        {
            picker.Format = DateTimePickerFormat.Custom;
            picker.CustomFormat = "dd/MM/yyyy HH:mm:ss";
        }

        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
        {
            return UITypeEditorEditStyle.DropDown;
        }

        public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
        {
            if (provider != null)
            {
                this.editorService = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
            }

            if (this.editorService != null)
            {
                picker.Value = value;
                this.editorService.DropDownControl(picker);
                value = picker.Value;
            }

            return value;
        }
    }
}

using System;

using System.ComponentModel;

using System.Drawing.Design;

using System.Windows.Forms;

using System.Windows.Forms.Design;

namespace Util

{

public class DateTimePickerEditor : UITypeEditor

{

IWindowsFormsEditorService editorService;

DateTimePicker picker = new DateTimePicker();

public DateTimePickerEditor()

{

picker.Format = DateTimePickerFormat.Custom;

picker.CustomFormat = "dd/MM/yyyy HH:mm:ss";

}

public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)

{

return UITypeEditorEditStyle.DropDown;

}

public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)

{

if (provider != null)

{

this.editorService = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;

}

if (this.editorService != null)

{

picker.Value = value;

this.editorService.DropDownControl(picker);

value = picker.Value;

}

return value;

}

Then in order to add that to your property grid, add the following to the DateTime item in the class used by the PropertyGrid –

[DisplayName("Start Time"), EditorAttribute(typeof(DateTimePickerEditor), typeof(UITypeEditor))]
public DateTime StartTime
{
    get { return startTime; }
    set { startTime = value; }
}

[DisplayName("Start Time"), EditorAttribute(typeof(DateTimePickerEditor), typeof(UITypeEditor))]

public DateTime StartTime

{

get { return startTime; }

set { startTime = value; }

}

The key part here is the EditorAttribute.

Update

Here’s a great article explaining custom UITypeEditors in more detail – http://bobpowell.net/TypeEditors.aspx

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Page 2 of 6

Maze Solving with A* In Python

Java Create Relative Date

Finished: Batman Arkham Origins

Finished: Dawn of War 2: Chaos Rising

Python Port Tunneler

Image Recognition Tool

Image Recognition with PyBrains

Ceaser Cipher Cracker

Fitbit Flex Bluetooth Syncing with HTC One X

C# DateTimePicker in PropertyGrid

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