issues: 794554881

Your code is full of open files that are never closed, especially when you deal with reading/writing json/yaml files.

If you run python with warnings enabled this problem becomes evident. This probably contributes to some memory leaks in long running datasettes if the GC will not 'collect' those resources properly.

This is easily fixed by using a context manager instead of just using open: python with open('some_file', 'w') as opened_file: opened_file.write('string')

In some newer parts of the code you use Path objects 'read_text' and 'write_text' functions which close the file properly and are prefered in some cases.

If you want I can create a PR for all places i found this pattern in.

Bellow is a fraction of places where i found a ResourceWarning: ```python

update-docs-help.py: 20 actual = actual.replace("Usage: cli ", "Usage: datasette ") 21: open(docs_path / filename, "w").write(actual) 22

datasette\app.py: 210 ): 211: inspect_data = json.load((config_dir / "inspect-data.json").open()) 212 if immutables is None:

266 if config_dir and (config_dir / "settings.json").exists() and not config: 267: config = json.load((config_dir / "settings.json").open()) 268 self._settings = dict(DEFAULT_SETTINGS, **(config or {}))

445 self._app_css_hash = hashlib.sha1( 446: open(os.path.join(str(app_root), "datasette/static/app.css")) 447 .read()

datasette\cli.py: 130 else: 131: out = open(inspect_file, "w") 132 loop = asyncio.get_event_loop()

459 if inspect_file: 460: inspect_data = json.load(open(inspect_file)) 461

```