This library is a python binding to universal chardet.
>>> from pychardet import detect_encoding
>>> detect_encoding('El castellano es la lengua española'.encode('iso-8859-1'))
{'encoding': 'iso-8859-1', 'confidence': 0.8775989413261414}
>>> from pychardet import detect_encoding
>>> detect_encoding(u"Réseau Démographie de l'Agence universitaire de la francophonie".encode('utf8'))
{'encoding': 'utf-8', 'confidence': 0.7524999976158142}
$ pip install pychardet