% ruff check --output-format=concise # https://docs.astral.sh/ruff

test/e2e-v2/cases/browser/docker/provider.py:19:20: F401 [*] `urllib.request` imported but unused
test/e2e-v2/cases/python/consumer.py:18:8: F401 [*] `urllib.parse` imported but unused
test/e2e-v2/cases/python/provider-kafka.py:20:20: F401 [*] `urllib.request` imported but unused
test/e2e-v2/cases/python/provider.py:20:20: F401 [*] `urllib.request` imported but unused
Found 4 errors.
[*] 4 fixable with the `--fix` option.

% ruff check --fix

Found 4 errors (4 fixed, 0 remaining).

% ruff rule F401

unused-import (F401)

Derived from the Pyflakes linter.

Fix is sometimes available.

What it does

Checks for unused imports.

Why is this bad?

Unused imports add a performance overhead at runtime, and risk creating
import cycles. They also increase the cognitive load of reading the code.

If an import statement is used to check for the availability or existence
of a module, consider using importlib.util.find_spec instead.

If an import statement is used to re-export a symbol as part of a module's
public interface, consider using a "redundant" import alias, which
instructs Ruff (and other tools) to respect the re-export, and avoid
marking it as unused, as in:

from module import member as member

Alternatively, you can use __all__ to declare a symbol as part of the module's
interface, as in:

# __init__.py
import some_module

__all__ = ["some_module"]

Fix safety

Fixes to remove unused imports are safe, except in __init__.py files.

Applying fixes to __init__.py files is currently in preview. The fix offered depends on the
type of the unused import. Ruff will suggest a safe fix to export first-party imports with
either a redundant alias or, if already present in the file, an __all__ entry. If multiple
__all__ declarations are present, Ruff will not offer a fix. Ruff will suggest an unsafe fix
to remove third-party and standard library imports -- the fix is unsafe because the module's
interface changes.

Example

import numpy as np  # unused import


def area(radius):
    return 3.14 * radius**2

Use instead:

def area(radius):
    return 3.14 * radius**2

To check the availability of a module, use importlib.util.find_spec:

from importlib.util import find_spec

if find_spec("numpy") is not None:
    print("numpy is installed")
else:
    print("numpy is not installed")

Options

• lint.ignore-init-module-imports
• lint.pyflakes.allowed-unused-imports

References

• Python documentation: import
• Python documentation: importlib.util.find_spec
• Typing documentation: interface conventions

Fix

• Add a unit test to verify that the fix works.
• Explain briefly why the bug exists and how to fix it.

Improve the performance of <class or module or ...>

• Add a benchmark for the improvement, refer to the existing ones
• The benchmark result.

<Paste the benchmark results here>

• Links/URLs to the theory proof or discussion articles/blogs. <links/URLs here>

• If this pull request closes/resolves/fixes an existing issue, replace the issue number. Closes #.
• Update the CHANGES log.