I tried something like this:
```python
print(r'{"foo": "\\\""}') 
print('{"foo": "\\\""}')
print(json.loads(r'{"foo":"\\\""}'))
```
On my machine it output like this:
```
{"foo": "\\\""}
{"foo": "\""}
{'foo': '\\"'}
```

But in most of online json parser, string `{"foo": "\\\""}` will be parsed as `{"foo":"\""}`

I'm not a specialist of JSON at all. If the standard of JSON hasn't said anything of it, please point it out in Python's Document at least.

When I ask my friend to run the code, he got the same result as me. And my friend is using lastest Arch Linux at that time(2019/08/26).

My python version: 3.7.4
System version: Linux 4.19.66-1-MANJARO