Method escape_value is not robust to encodings

[Farmhouse121]

It uses str uniformly. This breaks with differing or broken unicode encodings. It also does uncessary replace operations when the argument is not a string. The following works better:

def escape_value(self, data):
if data is None:
return ''

if type(data) in (str,unicode):
    data = data.encode(sys.getdefaultencoding(),"ignore")
    data = data.replace('&', '&amp;').replace('<', '&lt;').replace('>', '&gt;').replace('"', '&quot;')

else:
    data = str(data)

return data

[rysiekpl]

Run into this problem myself. Tested this solution, works like a charm.