Slotscheck

0.19.1 · active · verified Fri Apr 17

Slotscheck is a Python library that helps ensure your `__slots__` are working properly. It acts as a linter, identifying classes where `__slots__` might not be effective or are misused, thereby aiding in memory optimization and performance. The current version is 0.19.1, and it has a regular release cadence, often aligning with new Python versions.

Common errors

```
TypeError: 'module' object is not callable
```
cause You imported the entire `slotscheck` module (e.g., `import slotscheck`) and then tried to call the module itself as a function (e.g., `slotscheck(MyClass)`).

fix Import the specific function directly: `from slotscheck import slotscheck`. Then call it: `slotscheck(MyClass)`. Alternatively, if you `import slotscheck`, you must call `slotscheck.slotscheck(MyClass)`.
```
AttributeError: module 'slotscheck' has no attribute 'check_slots'
```
cause You're attempting to call a function named `check_slots`, which does not exist in the `slotscheck` library. The primary function for checking is also named `slotscheck`.

fix Use the correct function name: `from slotscheck import slotscheck` followed by `slotscheck(MyClass)`.
```
ImportError: cannot import name 'slotscheck' from 'slotscheck' (possibly due to a circular import)
```
cause This error often occurs if you have a local Python file named `slotscheck.py` in your project directory, which conflicts with the installed `slotscheck` package.

fix Rename your local file if it's named `slotscheck.py` to avoid name collisions. Ensure you're importing from the installed library, not a local file.

Warnings

breaking Python 3.8 support was dropped in `slotscheck` version `0.19.1`. If you are using Python 3.8, you must upgrade your Python interpreter or pin your `slotscheck` version.
Fix: Upgrade your Python environment to 3.9 or newer, or pin `slotscheck==0.18.0` in your project's dependencies.
breaking Python 3.7 support was dropped in `slotscheck` version `0.17.0`. Users on Python 3.7 will not be able to install or use newer versions.
Fix: Upgrade your Python environment to 3.8 or newer, or pin `slotscheck < 0.17.0` in your project's dependencies.
gotcha When using Python 3.12+, `Generic` classes could be incorrectly flagged as not having slots in `slotscheck` versions prior to `0.17.1`, leading to false positives.
Fix: Upgrade to `slotscheck >= 0.17.1` to resolve the false positive for `Generic` classes.
gotcha `TypedDict` imported from `typing_extensions` could be incorrectly flagged as not having slots in `slotscheck` versions prior to `0.16.5`, particularly in Python versions where `TypedDict` is already in the standard library.
Fix: Upgrade to `slotscheck >= 0.16.5` to correctly handle `TypedDict` instances.

Install

pip install slotscheck Install stable version

Imports

slotscheck
```
from slotscheck import slotscheck
```
The main function to check slots is named 'slotscheck', just like the library itself.

Quickstart

This quickstart demonstrates how to import and use the `slotscheck` function to verify `__slots__` implementation for individual classes. It shows examples of both a correctly slotted and an unslotted class, and how to get results from the checker. It can also be used to check entire modules.

from slotscheck import slotscheck

class MySlottedClass:
    __slots__ = ('x', 'y')

    def __init__(self, x, y):
        self.x = x
        self.y = y

class MyUnslottedClass:
    def __init__(self, x, y):
        self.x = x
        self.y = y

results_slotted = slotscheck(MySlottedClass)
print(f"MySlottedClass check results: {results_slotted}")

results_unslotted = slotscheck(MyUnslottedClass)
print(f"MyUnslottedClass check results: {results_unslotted}")

# To check an entire module (e.g., the current file):
# import sys
# current_module = sys.modules[__name__]
# module_results = slotscheck(current_module)
# print(f"Current module check results: {module_results}")

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