问如何使用lxml python获取textarea值

EN

import mechanize
import lxml.html
import StringIO

br = mechanize.Browser()
br.set_handle_robots(False)
br.addheaders = [("User-agent","Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101206 Ubuntu/10.10 (maverick) Firefox/3.6.13")]
sign_in = br.open("http://target.co.uk")
#the login url
br.select_form(nr = 0) 
#accessing form by their index.
#Since we have only one form in this example, nr =0.
br.select_form(nr=0)
#Alternatively you may use this instead of the above line 
#if your form has name attribute available.
br["username"] = "myusername"
#the key "username" is the variable that takes the username/email value
br["password"] = "myp4sw0rd"
#the key "password" is the variable that takes the password value
logged_in = br.submit()   
#submitting the login credentials
logincheck = logged_in.read()
#reading the page body that is redirected after successful login
if "logout" in logincheck:
    print "Login success, you just logged in."
else:
    print "Login failed"
#printing the body of the redirected url after login
coding1_content = br.open("https://www.target.co.uk/levels/coding/1").read() 
#accessing other url(s) after login is done this way


tree = lxml.html.parse(io.StringIO(coding1_content)

for ta in tree.findall("//textarea"):
    if not ta.get("name"):
        print(ta.text)

if "textarea" in coding1_content:
    print "Textarea found."
else:
    print "Textarea not found."

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<textarea>this, is, what, i, want</textarea>
<textarea name="answer">i don't need it</textarea>
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