Three ways to achieve wget over python:
import os, urllib, urllib2
# common
os.chdir("/home/jose")
picUrl = "http://www.google.com/intl/en/images/logo.gif"
# 1: using wget command
os.system("wget " + picUrl)
# 2: using urllib2
opener = urllib2.build_opener()
page = opener.open(picUrl)
pic = page.read() # the advantage is that pic holds the data in memory
file = open("logo2.gif", "wb")
file.write(pic)
file.close()
# 3: using urllib
urllib.urlretrieve(picUrl, "logo3.gif")