[Django]-Django can't process non-ascii symbols

In my case, replacing __ str__ method with __ unicode__ helped, but there are many factors at play here, as @bruno-desthuilliers said

# def __str__(self):
#     return str(self.id) +': ' + self.title

def __unicode__(self):
    return u'%s: %s' % (self.id, self.title)