Python RC with Color Prompt :)

pythonrc.py

# ~/.pythonrc

import sys

# enable syntax completion via tab
try:
    import readline
except ImportError:
    print "Module readline not available."
else:
    import rlcompleter
    readline.parse_and_bind("tab: complete")
    readline.parse_and_bind("bind ^I rl_complete") # for Mac OS X

try:
    import pprint
except:
    pass

import re
import sys
import os
import math
import random
import uuid
import hashlib
import datetime
import time
import getpass
import socket



def concat(*props):
    return ';'.join([ str(i) for i in props ])




class Prompt(object):

    CTRL_BASE = '\001\033[%sm\002'
    CTRL_RESET = '\001\033[0m\002'

    RE_PARSER_COLOR = re.compile(r'<([a-zA-Z]+)>')
    RE_PARSER_ATTRIB = re.compile('\{([a-zA-Z\_\-]+)\}')

    CODE_BOLD = 1
    CODE_DIM = 2
    CODE_UNDERLINE = 4
    CODE_BLINK = 5
    CODE_INVERT = 7
    CODE_HIDDEN = 8

    CODE_RESET_ALL = 0
    CODE_RESET_OFFSET = 20
    CODE_BACKGROUND_OFFSET = 10
    
    COLOR_DEFAULT = 39
    COLOR_BLACK = 30
    COLOR_RED = 31
    COLOR_GREEN = 32
    COLOR_YELLOW = 33
    COLOR_BLUE = 34
    COLOR_MAGENTA = 35
    COLOR_CYAN = 36
    COLOR_GRAY_LIGHT = 37
    COLOR_GRAY_DARK = 90
    COLOR_RED_LIGHT = 91
    COLOR_GREEN_LIGHT = 92
    COLOR_YELLOW_LIGHT = 93
    COLOR_BLUE_LIGHT = 94
    COLOR_MAGENTA_LIGHT = 95
    COLOR_CYAN_LIGHT = 96
    COLOR_WHITE = 97

    KEYWORDS = {
        "ERROR": (CTRL_BASE % (concat(COLOR_RED, CODE_BOLD, CODE_BLINK))),
        "red": (CTRL_BASE % (COLOR_RED)),
        "cyan": (CTRL_BASE % (COLOR_CYAN)),
        "yellow": (CTRL_BASE % (COLOR_YELLOW)),
        "green": (CTRL_BASE % (COLOR_GREEN)),
        "blue": (CTRL_BASE % (COLOR_BLUE)),
        "lightblue": (CTRL_BASE % (COLOR_BLUE_LIGHT)),
        "boldlightblue": (CTRL_BASE % (concat(COLOR_BLUE_LIGHT, CODE_BOLD))),
        "reset": (CTRL_RESET)
    }

    
    @classmethod
    def colorize(cls, text):
        return cls.RE_PARSER_COLOR.sub(lambda m: cls.KEYWORDS.get(m.group(1), ''), text)


    @property
    def user(self):
        return getpass.getuser()

    @property
    def host(self):
        return socket.gethostname()

    @property
    def path(self):
        rel = os.path.relpath(os.curdir, os.path.expanduser('~'))
        if rel.startswith('..'):
            return os.path.abspath(os.curdir)
        elif rel == '.':
            return '~'
        else:
            return (rel or '~')

    @property
    def time(self):
        return datetime.datetime.now().time().strftime('%H:%M:%S')
   
    @property
    def pyversion(self):
        info = sys.version_info
        return '%d.%d' % info[0:2]

    def __init__(self, prompt_format):
        self.prompt_format = prompt_format
   
    def __str__(self):
        basetext = self.RE_PARSER_ATTRIB.sub(lambda m: getattr(self, m.group(1), ''), self.prompt_format)
        return  self.colorize(basetext) + self.CTRL_RESET


print Prompt.colorize('You are in <cyan>python.<reset>\n') + Prompt.CTRL_RESET

sys.ps1 = Prompt("<cyan>python<reset><red>{pyversion} <yellow>{time} <green>{user}<reset>@<yellow>{host} <boldlightblue>{path}<reset> > ")
sys.ps2 = '<yellow>..><reset> '

#sys.ps1 = '\001\033[96m\002py> \001\033[0m\002'
#sys.ps2 = '\001\033[96m\002..> \001\033[0m\002'


# vim: ft=python

I have an issue where if I arrow up into command history, the interactive interpreter assumes that the start of the line is further to the right than it should be. Do you have any insight into this?