Can you please add a description to explain the report?

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

I hope I have given enough infomations. And I'm not good at English, please forgive some of my spell wrong, thanks.

I'm sorry that I remove you from list, actually it's my first time to commit an issue on there and I'm afraid I used it wrong.

There is no a bug.

"\\\"" is the same as r"\\" -- a 2-charackter string consisting of a backslash character and a doublequote character. r"\\\"" is a different string, it contains 3 backslash characters.

>>> print("\\\"")
\"
>>> print(repr("\\\""))
'\\"'