ResourceWarning: unclosed file

[djhenderson]

Issuing either

py -Wdefault -m sqlite_utils insert dogs.db dogs dogs0.csv --csv
  [#############-----------------------]   36%
  [####################################]  100%C:\Users\Doug\AppData\Local\Programs\Python\Python311\Lib\site-packages\sqlite_utils\cli.py:1187: ResourceWarning: unclosed file <_io.TextIOWrapper name='dogs0.csv' encoding='utf-8-sig'>
  insert_upsert_implementation(
ResourceWarning: Enable tracemalloc to get the object allocation traceback

or

set pythonwarnings=default
sqlite-utils insert dogs.db dogs dogs0.csv --csv
  [#############-----------------------]   36%
  [####################################]  100%C:\Users\Doug\AppData\Local\Programs\Python\Python311\Lib\site-packages\sqlite_utils\cli.py:1187: ResourceWarning: unclosed file <_io.TextIOWrapper name='dogs0.csv' encoding='utf-8-sig'>
  insert_upsert_implementation(
ResourceWarning: Enable tracemalloc to get the object allocation traceback

exhibits a ResourceWarning indicating that the CSV file being loaded is not closed.

sqlite-utils --version
sqlite-utils, version 3.30
py --version
Python 3.11.2
Windows Version 10.0.19045 Build 19045
SQLite version 3.41.0 2023-02-21 18:09:37

[simonw]

On macOS this shows the same warning:

% python -Wdefault $(which sqlite-utils) insert dogs.db dogs dogs.csv --csv
  [############------------------------]   35%
  [####################################]  100%/Users/simon/Dropbox/Development/sqlite-utils/sqlite_utils/cli.py:1187: ResourceWarning: unclosed file <_io.TextIOWrapper name='dogs.csv' encoding='utf-8-sig'>
  insert_upsert_implementation(
ResourceWarning: Enable tracemalloc to get the object allocation traceback

The file itself is a click.File which is automatically closed - https://click.palletsprojects.com/en/8.1.x/api/#click.File - but it looks like it's the _io.TextIOWrapper which is not being closed:

sqlite-utils/sqlite_utils/cli.py

Lines 949 to 956 in 2376c45

	# The --sniff option needs us to buffer the file to peek ahead
	sniff_buffer = None
	if sniff:
	sniff_buffer = io.BufferedReader(file, buffer_size=4096)
	decoded = io.TextIOWrapper(sniff_buffer, encoding=encoding)
	else:
	decoded = io.TextIOWrapper(file, encoding=encoding)