Resource not released (ARCH2080)

Key python.performance.disposable-not-disposed · Severity error · Category performance

When a resource-owning object is created without a with block, an error before cleanup leaves it unreleased and leaks it. Use a context manager.

Incorrect

def write_report(path, data):
    lock = acquire_lock("report")
    f = open(path, "w")
    f.write(data)
    f.close()
    lock.release()

Correct

def write_report(path, data):
    with acquire_lock("report"), open(path, "w") as f:
        f.write(data)

Fix

Wrap resource-owning objects in a with context manager so they are released on exit.