SIM115.py

import contextlib
import pathlib
import pathlib as pl
from pathlib import Path
from pathlib import Path as P

# SIM115
f = open("foo.txt")
f = Path("foo.txt").open()
f = pathlib.Path("foo.txt").open()
f = pl.Path("foo.txt").open()
f = P("foo.txt").open()
data = f.read()
f.close()

# OK
with open("foo.txt") as f:
    data = f.read()

# OK
with contextlib.ExitStack() as exit_stack:
    f = exit_stack.enter_context(open("filename"))

# OK
with contextlib.ExitStack() as stack:
    files = [stack.enter_context(open(fname)) for fname in filenames]
    close_files = stack.pop_all().close

# OK
with contextlib.AsyncExitStack() as exit_stack:
    f = await exit_stack.enter_async_context(open("filename"))

# OK (false negative)
with contextlib.ExitStack():
    f = exit_stack.enter_context(open("filename"))

# SIM115
with contextlib.ExitStack():
    f = open("filename")

# OK
with contextlib.ExitStack() as exit_stack:
    exit_stack_ = exit_stack
    f = exit_stack_.enter_context(open("filename"))

# OK (quick one-liner to clear file contents)
open("filename", "w").close()
pathlib.Path("filename").open("w").close()

# OK (custom context manager)
class MyFile:
    def __init__(self, filename: str):
        self.filename = filename

    def __enter__(self):
        self.file = open(self.filename)

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.file.close()


import tempfile
import tarfile
from tarfile import TarFile
import zipfile
import io
import codecs
import bz2
import gzip
import dbm
import dbm.gnu
import dbm.ndbm
import dbm.dumb
import lzma
import shelve
import tokenize
import wave
import fileinput

f = tempfile.NamedTemporaryFile()
f = tempfile.TemporaryFile()
f = tempfile.SpooledTemporaryFile()
f = tarfile.open("foo.tar")
f = TarFile("foo.tar").open()
f = tarfile.TarFile("foo.tar").open()
f = tarfile.TarFile().open()
f = zipfile.ZipFile("foo.zip").open("foo.txt")
f = io.open("foo.txt")
f = io.open_code("foo.txt")
f = codecs.open("foo.txt")
f = bz2.open("foo.txt")
f = gzip.open("foo.txt")
f = dbm.open("foo.db")
f = dbm.gnu.open("foo.db")
f = dbm.ndbm.open("foo.db")
f = dbm.dumb.open("foo.db")
f = lzma.open("foo.xz")
f = lzma.LZMAFile("foo.xz")
f = shelve.open("foo.db")
f = tokenize.open("foo.py")
f = wave.open("foo.wav")
f = tarfile.TarFile.taropen("foo.tar")
f = fileinput.input("foo.txt")
f = fileinput.FileInput("foo.txt")

with contextlib.suppress(Exception):
    # The following line is for example's sake.
    # For some f's above, this would raise an error (since it'd be f.readline() etc.)
    data = f.read()

f.close()

# OK
with tempfile.TemporaryFile() as f:
    data = f.read()

# OK
with tarfile.open("foo.tar") as f:
    data = f.add("foo.txt")

# OK
with tarfile.TarFile("foo.tar") as f:
    data = f.add("foo.txt")

# OK
with tarfile.TarFile("foo.tar").open() as f:
    data = f.add("foo.txt")

# OK
with zipfile.ZipFile("foo.zip") as f:
    data = f.read("foo.txt")

# OK
with zipfile.ZipFile("foo.zip").open("foo.txt") as f:
    data = f.read()

# OK
with zipfile.ZipFile("foo.zip") as zf:
    with zf.open("foo.txt") as f:
        data = f.read()

# OK
with io.open("foo.txt") as f:
    data = f.read()

# OK
with io.open_code("foo.txt") as f:
    data = f.read()

# OK
with codecs.open("foo.txt") as f:
    data = f.read()

# OK
with bz2.open("foo.txt") as f:
    data = f.read()

# OK
with gzip.open("foo.txt") as f:
    data = f.read()

# OK
with dbm.open("foo.db") as f:
    data = f.get("foo")

# OK
with dbm.gnu.open("foo.db") as f:
    data = f.get("foo")

# OK
with dbm.ndbm.open("foo.db") as f:
    data = f.get("foo")

# OK
with dbm.dumb.open("foo.db") as f:
    data = f.get("foo")

# OK
with lzma.open("foo.xz") as f:
    data = f.read()

# OK
with lzma.LZMAFile("foo.xz") as f:
    data = f.read()

# OK
with shelve.open("foo.db") as f:
    data = f["foo"]

# OK
with tokenize.open("foo.py") as f:
    data = f.read()

# OK
with wave.open("foo.wav") as f:
    data = f.readframes(1024)

# OK
with tarfile.TarFile.taropen("foo.tar") as f:
    data = f.add("foo.txt")

# OK
with fileinput.input("foo.txt") as f:
    data = f.readline()

# OK
with fileinput.FileInput("foo.txt") as f:
    data = f.readline()

# OK (quick one-liner to clear file contents)
tempfile.NamedTemporaryFile().close()
tempfile.TemporaryFile().close()
tempfile.SpooledTemporaryFile().close()
tarfile.open("foo.tar").close()
tarfile.TarFile("foo.tar").close()
tarfile.TarFile("foo.tar").open().close()
tarfile.TarFile.open("foo.tar").close()
zipfile.ZipFile("foo.zip").close()
zipfile.ZipFile("foo.zip").open("foo.txt").close()
io.open("foo.txt").close()
io.open_code("foo.txt").close()
codecs.open("foo.txt").close()
bz2.open("foo.txt").close()
gzip.open("foo.txt").close()
dbm.open("foo.db").close()
dbm.gnu.open("foo.db").close()
dbm.ndbm.open("foo.db").close()
dbm.dumb.open("foo.db").close()
lzma.open("foo.xz").close()
lzma.LZMAFile("foo.xz").close()
shelve.open("foo.db").close()
tokenize.open("foo.py").close()
wave.open("foo.wav").close()
tarfile.TarFile.taropen("foo.tar").close()
fileinput.input("foo.txt").close()
fileinput.FileInput("foo.txt").close()

def aliased():
    from shelve import open as open_shelf
    x = open_shelf("foo.dbm")
    x.close()

    from tarfile import TarFile as TF
    f = TF("foo").open()
    f.close()

import dbm.sqlite3

# OK
with dbm.sqlite3.open("foo.db") as f:
    print(f.keys())

# OK
dbm.sqlite3.open("foo.db").close()

# SIM115
f = dbm.sqlite3.open("foo.db")
f.close()

# OK
def func(filepath, encoding):
    return open(filepath, mode="rt", encoding=encoding)

# OK
def func(filepath, encoding):
    return f(open(filepath, mode="rt", encoding=encoding))


from unittest import IsolatedAsyncioTestCase, TestCase

# OK
class ExampleClassTests(TestCase):
    @classmethod
    def setUpClass(cls):
        cls.enterClassContext(open("filename"))

# OK
class ExampleAsyncTests(IsolatedAsyncioTestCase):
    async def test_something(self):
        await self.enterAsyncContext(open("filename"))

# OK
class ExampleTests(TestCase):
    def setUp(self):
        self.enterContext(open("filename"))