Bad JSON subclass can produce invalid JSON #123183
Description
Bug report
Bug description:
import io
import json
class BadDict(dict):
def __len__(self) -> int:
return 1
class BadList(list):
def __len__(self) -> int:
return 1
fp = io.StringIO()
json.dump([BadDict(), BadList()], fp, indent=4)
print(fp.getvalue())[
{
},
]
]CPython versions tested on:
3.12
Operating systems tested on:
Windows