PS: I bought the B+ model. And my code is the same as yours:


##Much of this code comes from Dexter Industries' GoPiGo with office cannon script, with minor changes for user-input from a keyboard.
##
## http://www.dexterindustries.com/GoPiGo/                                                                
## History
## ------------------------------------------------
## Author     Date       Comments
## John Cole   April 14   Initial Authoring    
## Karan 27 June 14 Code cleanup and made more responsive  
## 25 Aug  14 USB high current mode for Raspberry Pi Model B+ added        
##                                      
##
##
##License
##GoPiGo for the Raspberry Pi: an open source robotics platform for the Raspberry Pi.
## Copyright (C) 2015  Dexter Industries
##
##This program is free software: you can redistribute it and/or modify
##it under the terms of the GNU General Public License as published by
##the Free Software Foundation, either version 3 of the License, or
##(at your option) any later version.
##
##This program is distributed in the hope that it will be useful,
##but WITHOUT ANY WARRANTY; without even the implied warranty of
##MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
##GNU General Public License for more details.
##
##You should have received a copy of the GNU General Public License
##along with this program.  If not, see .

import Tkinter as tk
from gopigo import *

servo_range = [2,3,4,5,6,7,8]


import struct
import os

import sys
import platform
import time
import socket
import re
import json
import urllib2
import base64

import usb.core
import usb.util

#Enable for Model B+ and disable for Model B
model_b_plus=True # For the model B+ we need to turn this variable on to run the Office Cannon.
# This can be left on for the Model B and not cause problems.
# This pulls GPIO 38 to high, which overrides USB overcurrent setting.
# With this set, the USB can deliver up to 1.2 Amps.
tdelay=80
# Protocol command bytes
DOWN    = 0x01
UP      = 0x02
LEFT    = 0x04
RIGHT   = 0x08
FIRE    = 0x10
STOP    = 0x20

DEVICE = None
DEVICE_TYPE = None

file = open( "/dev/input/mice", "rb" );
debug = 0

# Setup the Office Cannon
def setup_usb():
    global DEVICE
    global DEVICE_TYPE

    DEVICE = usb.core.find(idVendor=0x2123, idProduct=0x1010)

    if DEVICE is None:
        DEVICE = usb.core.find(idVendor=0x0a81, idProduct=0x0701)
        if DEVICE is None:
            raise ValueError('Missile device not found')
        else:
            DEVICE_TYPE = "Original"
    else:
        DEVICE_TYPE = "Thunder"

    # On Linux we need to detach usb HID first
    if "Linux" == platform.system():
        try:
            DEVICE.detach_kernel_driver(0)
        except Exception, e:
            pass # already unregistered    
    DEVICE.set_configuration()

#Send command to the office cannon
def send_cmd(cmd):
    if "Thunder" == DEVICE_TYPE:
        DEVICE.ctrl_transfer(0x21, 0x09, 0, 0, [0x02, cmd, 0x00,0x00,0x00,0x00,0x00,0x00])
    elif "Original" == DEVICE_TYPE:
        DEVICE.ctrl_transfer(0x21, 0x09, 0x0200, 0, [cmd])

#Send command to control the LED on the office cannon
def led(cmd):
    if "Thunder" == DEVICE_TYPE:
        DEVICE.ctrl_transfer(0x21, 0x09, 0, 0, [0x03, cmd, 0x00,0x00,0x00,0x00,0x00,0x00])
    elif "Original" == DEVICE_TYPE:
        print("There is no LED on this device")

#Send command to move the office cannon
def send_move(cmd, duration_ms):
    send_cmd(cmd)
    time.sleep(duration_ms / 1000.0)
    send_cmd(STOP)

def run_command(command, value):
    command = command.lower()
    if command == "right":
        send_move(RIGHT, value)
    elif command == "left":
        send_move(LEFT, value)
    elif command == "up":
        send_move(UP, value)
    elif command == "down":
        send_move(DOWN, value)
    elif command == "zero" or command == "park" or command == "reset":
        # Move to bottom-left
        send_move(DOWN, 2000)
        send_move(LEFT, 8000)
    elif command == "pause" or command == "sleep":
        time.sleep(value / 1000.0)
    elif command == "led":
        if value == 0:
            led(0x00)
        else:
            led(0x01)
    elif command == "fire" or command == "shoot":
        if value < 1 or value > 4:
            value = 1
        # Stabilize prior to the shot, then allow for reload time after.
        time.sleep(0.5)
        for i in range(value):
            send_cmd(FIRE)
            time.sleep(4.5)
    else:
        print "Error: Unknown command: '%s'" % command

def run_command_set(commands):
    for cmd, value in commands:
        run_command(cmd, value)

#Read the values from the mouse
def getMouseEvent():
buf = file.read(3)
button = ord( buf[0] )
bLeft = button & 0x1
bMiddle = ( button & 0x4 ) > 0
bRight = ( button & 0x2 ) > 0
x,y = struct.unpack( "bb", buf[1:] )
if debug:
print ("L:%d, M: %d, R: %d, x: %d, y: %dn" % (bLeft,bMiddle,bRight, x, y) )
return [bLeft,bMiddle,bRight,x,y]
  
  
flag=0
#Control the office cannon
def control():
global flag
[bLeft,bMiddle,bRight,x,y]=getMouseEvent()  #Get the inputs from the mouse

#GoPiGo control
if flag==1: #If left or right mouse not pressed, move forward
fwd()
flag=0
if bLeft:     #If left mouse buton pressed, turn left
left()
flag=1
  
if bRight:     #If right mouse button presses, turn right
right()
flag=1
if bLeft and bRight:   #If both the left and right mouse buttons pressed, go back
stop()
flag=0

#Office cannon control

if bMiddle > 0:
print "fire rockets"
run_command("fire", tdelay)

#Move the mouse left to move the cannon left
#Move the mouse right to move the cannon right
#Press middle button to fire

if x == 0:
print "Stop rockets"
elif x > 10:
print "Left rockets"
run_command("left", tdelay)
elif x < -10:
print "Right rockets"
run_command("right", tdelay)
if y == 0:
print "Stop Rockets Y"
elif y > 10:
print "Up Rockets"
run_command("up", tdelay)
elif y < -10:
print "Down rockets"
run_command("down", tdelay)

time.sleep(.1)
return


def key_input(event):
    key_press = event.keysym.lower()
    print(key_press)

    if key_press == 'w':
        fwd()
    elif key_press == 's':
        bwd()
    elif key_press == 'a':
        left()
    elif key_press == 'd':
        right()
    elif key_press == 'q':
        left_rot()
    elif key_press == 'e':
        right_rot()
    elif key_press == 'space':
        stop()
    elif key_press == 'u':
        print(us_dist(15))

    elif key_press.isdigit():
        if int(key_press) in servo_range:
            enable_servo()
            servo(int(key_press)*14)
            time.sleep(1)
            disable_servo()

    elif key_press == 'control_r' or key_press == 'control_l':
        print('Fire rockets!')
        run_command("fire", tdelay)

    elif key_press == 'left':
        print('Left rockets')
        run_command('left', tdelay)
    elif key_press == 'right':
        print('right rockets')
        run_command('right', tdelay)
    elif key_press == 'up':
        print('up rockets')
        run_command('up', tdelay)
    elif key_press == 'down':
        print('down rockets')
        run_command('down', tdelay)


setup_usb()

#Enable USB to give supply upto 1.2A on model B+
if model_b_plus:
        os.system("gpio -g write 38 0")
        os.system("gpio -g mode 38 out")
        os.system("gpio -g write 38 1")

run_command("zero", 100)
stop()        

command = tk.Tk()
command.bind_all('<Key>', key_input)
command.mainloop()

control_r and control_l are the control keys if i recall correct. The keys with "ctrl" on them.