smart_str.py

# Returns a bytestring version of 's', encoded as specified in 'encoding'.

def smart_str(s, encoding='utf-8', errors='strict'):
    """
    Returns a bytestring version of 's', encoded as specified in 'encoding'.
    """
    if not isinstance(s, basestring):
        try:
            return str(s)
        except UnicodeEncodeError:
            return unicode(s).encode(encoding, errors)
    elif isinstance(s, unicode):
        return s.encode(encoding, errors)
    elif s and encoding != 'utf-8':
        return s.decode('utf-8', errors).encode(encoding, errors)
    else:
        return s