在使用pyqt4和requests库遇到的问题

from PyQt4 import QtGui, QtCore, QtNetwork,QtWebKit

import requests



def download(webview,url):

    loop = QtCore.QEventLoop()

    webview.loadFinished.connect(loop.quit)

    req = QtNetwork.QNetworkRequest(QtCore.QUrl(url))

    webview.load(req)

    loop.exec_()



app = QtGui.QApplication([])

webview = QtWebKit.QWebView()

webview.show()

download(webview,'https://passport.baidu.com/v2/?login')

frame = webview.page().mainFrame()

frame.findFirstElement('#TANGRAM__PSP_3__userName').setAttribute('value','username')

frame.findFirstElement('#TANGRAM__PSP_3__password').setAttribute('value','password')

frame.findFirstElement('#TANGRAM__PSP_3__submit').evaluateJavascript("this.click()")

#等待结果

elements = QtWebKit.QWebElement()

while elements.isNull():

    #每次循环，都会调用app.processEvents(),用于给Qt事件循环执行任务的时间，比如响应点击事件和更新GUI

    app.processEvents()

    elements = frame.findFirstElement('#displayUsername')



s_COOKIEs = {}

for citem in webview.page().networkAccessManager().COOKIEJar().COOKIEsForUrl(QtCore.QUrl('http://www.baidu.com')):

    s_COOKIEs[bytes(citem.name()).decode()] = bytes(citem.value()).decode()



webview.close()

s = requests.Session()

s.headers = {

        'Accept':'text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8',

        'Accept-Encoding':'gzip, deflate, sdch',

        'Accept-Language':'zh-CN,zh;q=0.8',

        'Connection':'keep-alive',

        'User-Agent':'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.72 Safari/537.36',

        }

s.COOKIEs.update(s_COOKIEs)

r = s.get('http://tieba.baidu.com/p/5007359263')

print(r.status_code)

with open('tieba.html','w') as f:

    f.write(r.text)

for citem in webview.page().networkAccessManager().COOKIEJar().COOKIEsForUrl(QtCore.QUrl('http://www.baidu.com')):

    s_COOKIEs[bytes(citem.name()).decode()] = bytes(citem.value()).decode()