send to twitter

[Torvalds]

amigos, queria saber si podrian determinar porque el siguiente codigo no funciona, porque la verdad que no tiene logica, todo lo veo perfecto, no soy tan experimentado en python, a ver si ustedes pueden ayudarme, de antemano muchas gracias.

Código Python:

import urllib.request 
import time
 
password="yourpass" 
 
def send_to_twitter(msg): 
    password_manager = urllib.request.HTTPPasswordMgr() 
    password_manager.add_password("Twitter API", 
                   "http://twitter.com/statuses", "YourUsername", password) 
    http_handler = urllib.request.HTTPBasicAuthHandler(password_manager) 
    page_opener = urllib.request.build_opener(http_handler) 
    urllib.request.install_opener(page_opener) 
    params = urllib.parse.urlencode( {'status': msg} ) 
    resp = urllib.request.urlopen("http://twitter.com/statuses/update.json", params) 
    resp.read()
 
def get_price(): 
    page = urllib.request.urlopen("http://www.beans-r-us.biz/prices.html") 
    text = page.read().decode("utf8") 
    where = text.find('>$') 
    start_of_price = where + 2 
    end_of_price = start_of_price + 4 
    return float(text[start_of_price:end_of_price]) 
 
price_now = input("Do you want to see the price now (Y/N)? ") 
 
if price_now == "Y": 
    send_to_twitter(get_price()) 
else: 
    price = 99.99 
    while price > 4.74: 
        time.sleep(900) 
        price = get_price() 
    send_to_twitter("Buy!")
 

y aqui el error que me muestra el interprete


Traceback (most recent call last):
File "C:\Users\Marino\Documents\Pycode\hfprog_resources \Chapter 3\page108.py", line 28, in <module>
send_to_twitter(get_price())
File "C:\Users\Marino\Documents\Pycode\hfprog_resources \Chapter 3\page108.py", line 14, in send_to_twitter
resp = urllib.request.urlopen("http://twitter.com/statuses/update.json", params)
File "C:\Python32\lib\urllib\request.py", line 138, in urlopen
return opener.open(url, data, timeout)
File "C:\Python32\lib\urllib\request.py", line 364, in open
req = meth(req)
File "C:\Python32\lib\urllib\request.py", line 1052, in do_request_
raise TypeError("POST data should be bytes"
TypeError: POST data should be bytes or an iterable of bytes. It cannot be str.