1  See also: [[Using Python on macOS]].
 2  
 3  We will use a very simple Python script to validate encodings. You can find the script here: https://gist.github.com/marcinczenko/a87baf506bb0fd4bdff752cda4c685a1
 4  
 5  Our input will be the following `data1M.bin.torrent.json` file:
 6  
 7  ```nim
 8  {
 9    "info": {
10      "length": 1048576,
11      "name": "data1M.bin",
12      "piece length": 262144,
13      "pieces": [
14        "111421FEBA308CD51E9ACF88417193A9EA60F0F84646",
15        "11143D4A8279853DA2DA355A574740217D446506E8EB",
16        "11141AD686B48B9560B15B8843FD00E7EC1B59624B09",
17        "11145015E7DA0C40350624C6B5A1FED1DB39720B726C"
18      ]
19    }
20  }
21  ```
22  
23  To *b-encode* we run:
24  
25  ```bash
26  python bencoder.py --info-only data1M.bin.torrent.json
27  Using values from file: data1M.bin.torrent.json
28  Info only: True
29  {
30    "length": 1048576,
31    "name": "data1M.bin",
32    "piece length": 262144,
33    "pieces": [
34      "21FEBA308CD51E9ACF88417193A9EA60F0F84646",
35      "3D4A8279853DA2DA355A574740217D446506E8EB",
36      "1AD686B48B9560B15B8843FD00E7EC1B59624B09",
37      "5015E7DA0C40350624C6B5A1FED1DB39720B726C"
38    ]
39  }
40  infohash f335440998515770adf47e8a4626889e59d91dde
41  ```
42  
43  The `--info-only` option instructs the script to only b-encode the info dictionary and do not include other attributes like `announce`.
44  
45  We get as an output the `data1M.bin.torrent` file with the following content:
46  
47  ```bash
48  d4:infod6:lengthi1048576e4:name10:data1M.bin12:piece lengthi262144e6:pieces80:!��0���ψAq���`��FF=J�y�=��5ZWG@!}De��ֆ���`�[�C���YbK	P��@5$Ƶ����9rrlee
49  ```
50  
51  It is not very readable, because pieces has been converted to hex strings to a flattened byte array - in the end this is supposed to be machine readable code.