or even

```python
hack_log_json_format = '--pretty=format:{kwargs}'.format(kwargs=josn.dumps({
    "sha": "%H", 
    "author": "%an <%ae>",
    "date": "%ai",
    "subject": "##hackescape1##%s##hackescape2##",
    "message": "##hackescape3##%b##hackescape4##"
}))
```