# Week 3

## Python Debugging ##

######################################################################
# Autoload debugger

# sitecustomize.py
# from http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65287
#
# code snippet, to be included in 'sitecustomize.py'
# 'sitecustomize.py' needs to be in the python path,
# such as in the site-packages directory
import sys

def info(type, value, tb):
   if hasattr(sys, 'ps1') or not sys.stderr.isatty():
      # we are in interactive mode or we don't have a tty-like
      # device, so we call the default hook
      sys.__excepthook__(type, value, tb)
   else:
      import traceback, pdb
      # we are NOT in interactive mode, print the exception...
      traceback.print_exception(type, value, tb)
      print
      # ...then start the debugger in post-mortem mode.
      pdb.pm()

sys.excepthook = info

######################################################################
# Buggy program example

import math
import sitecustomize

def factorize():
    print "Number to factorize: ",
    a = raw_input()
    for i in primes(math.sqrt(a)):
        while (a % i == 0) :
            a = a / i
            result.append(i)
    print result

def isPrime(n):
    if n == 2:
        return True
    else:
        return primeCheck(n, primes(int(math.sqrt(n))))
        
def primeCheck(n, l):
    return n%l[0] and primeCheck(n,l[1:])

def primes(n):
    return filter(isPrime, range(2, n+1))

if __name__ == "__main__":
    factorize()