This is a simple way to demonstrate how the python file can rewrite it's own source code. This is particularly useful for checking if the program is first run or not. Something like that.

algorithm.py

import sys

con = '#'

if __name__ == '__main__':
	fname = sys.argv[0]

	content = open(fname).read()
	newfile = open(fname,'w')

	if chr(35) in content:
		content = content.replace(chr(35),chr(47))
		print"Changed %s to %s" % (chr(35),chr(47))
	elif chr(47) in content:
		content = content.replace(chr(47),chr(35))
		print "Changed %s to %s" % (chr(47),chr(35))

	newfile.write(content)
	newfile.close()