how to detect the character encoding in a web page ?

[iMath]

在 2012年12月24日星期一UTC+8上午8时34分47秒，iMath写道：
> how to detect the character encoding  in a web page ?
> 
> such as this page 
> 
> 
> 
> http://python.org/

I found PyQt’s QtextStream can  very accurately detect the character encoding in a web page .
even for this bad page 

chardet and beautiful soup failed ,but QtextStream can get the right result .

here is my code 

from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtNetwork  import *
import sys
def slotSourceDownloaded(reply):
    redirctLocation=reply.header(QNetworkRequest.LocationHeader)
    redirctLocationUrl=reply.url() if not redirctLocation else redirctLocation
    print(redirctLocationUrl)
  
    if (reply.error()!= QNetworkReply.NoError):
        print('11111111', reply.errorString())
        return
  
    content=QTextStream(reply).readAll()
    if content=='':
        print('---------', 'cannot find any resource !')
        return
 
    print(content)
     
    reply.deleteLater()
    qApp.quit()
 
 
if __name__ == '__main__':
    app =QCoreApplication(sys.argv)
    manager=QNetworkAccessManager ()
    url =input('input url :')
    request=QNetworkRequest (QUrl.fromEncoded(QUrl.fromUserInput(url).toEncoded()))
    request.setRawHeader("User-Agent" ,'Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.57 Safari/537.17 SE 2.X MetaSr 1.0')
    manager.get(request)
    manager.finished.connect(slotSourceDownloaded)
    sys.exit(app.exec_())