Simply shows the bitcoin price in $ from mtgox.com and the total price of all the bitcoins you own. Screenshot: http://i.imgur.com/UatFwkM.png

bitcoin_watch.py

# -*- coding: utf-8 -*-

# Simply shows the bitcoin price in $ from mtgox.com and the total price of all the bitcoins you own.
# Screenshot: http://i.imgur.com/UatFwkM.png
# Donations --> 1HpQQds9wUFykgwKyzXp747SAb6374RjUL

import requests
import json
from time import sleep
from sys import stdout
import argparse
import locale

parser = argparse.ArgumentParser(description='Bitcoin watch')
parser.add_argument('bitcoins', type=float, help='how much bitcoins do you own?')
parser.add_argument('--proxy', type=str, default='', help='http proxy')
parser.add_argument('--interval', type=int, default=5, help='refresh interval')

args = parser.parse_args()

if args.interval < 1:
    args.interval = 1

if args.proxy:
    proxies = {"http": args.proxy}
else:
    proxies = None


class c:
    FALL = '\033[%s;31m'
    RISE = '\033[%s;32m'
    ENDC = '\033[0m'
    TOTAL = '\033[1;30m'
    CLEAR = '\033[2J\033[;H'


def spinner():
    items = ['—', '\\', '|', '/']
    while True:
        for item in items:
            yield item

last_price = 0
changed = 0
color = c.RISE

the_spinner = spinner()

while True:
    try:
        #r = requests.get('http://data.mtgox.com/api/1/BTCUSD/ticker', proxies=proxies)
        #price = float(data['return']['last']['value'])
        r = requests.get('http://data.mtgox.com/api/2/BTCUSD/money/ticker_fast', proxies=proxies)
        data = json.loads(r.content)
        price = float(data['data']['last']['value'])
    except:
        price = -1

    if price > last_price:
        color = c.RISE
        changed = 1
    elif price < last_price:
        color = c.FALL
        changed = 1
    else:
        changed = 0

    total_price = args.bitcoins * price

    if total_price < 100:  # show decimal points under $100
        total_format = '%0.2f'
    else:
        total_format = '%d'

    total_price = locale.format(total_format, total_price, grouping=True)

    stdout.write('%s$%s%0.2f %s%s %s(%s)%s' % (c.CLEAR, color % changed, price, c.ENDC, next(the_spinner), c.TOTAL, total_price, c.ENDC))
    stdout.flush()

    last_price = price

    sleep(args.interval)

Some changes to consider:

def spinner():
    items = ['—', '\\', '|', '/',]
    while True:
        for item in items:
            yield item

There's also no need to use vars() with argparse, you can access the fields with:

args = parser.parse_args()
args.bitcoins
# ...

@moshekapian: thanks!

Needs to be updated since mtgox.com failed.