dump django queryset object to yaml

dump_queryset.py

def dump_queryset(qs, format='yaml', indent=2, filename=None):
    """ QuerySet をカレントディレクトリにyamlで出力するCLI Utility """
    if not isinstance(qs, QuerySet):
        raise ValueError(u'QuerySet以外はシリアライズできません')

    data = serializers.serialize(format, qs, indent=indent)

    if not filename:
        model_name = qs[0].__class__.__name__
        now_str = datetime.now().strftime('%Y_%M_%d__%H_%M_%S')
        filename = model_name + '_Dump_' + now_str + '.' + format

    f = open(filename, 'w')
    f.write(data)
    f.close()