passagemath-categories

10.8.4 verified Fri May 01 auth: no python

Part of the passagemath ecosystem, providing SageMath's category framework and basic rings. Current version 10.8.4, Python 3.11-3.14. Released every few months alongside passagemath releases.

pip install passagemath-categories

Common errors

error ModuleNotFoundError: No module named 'passagemath' ↓

cause Assuming the package exposes a top-level 'passagemath' module. Actually it uses the 'sage' namespace.

fix

Install passagemath-categories and use 'from sage.categories import ...'.

error ImportError: cannot import name 'Category' from 'sage.categories' ↓

cause Trying to import Category directly from sage.categories instead of sage.categories.category.

fix

Use 'from sage.categories.category import Category'.

error TypeError: 'module' object is not callable ↓

cause Calling Rings() before importing the class; or using Rings as a module.

fix

Use 'from sage.categories.rings import Rings; Rings()'.

Warnings

breaking passagemath-categories 10.8 splits off category framework from monolithic sage. Old 'from sage.all import *' still works but may break if you previously relied on sage.categories being loaded by default. ↓

fix Ensure 'passagemath-categories' is installed and import explicitely from sage.categories.

deprecated Some old categories like 'SetsWithPartialMaps' are deprecated or removed. Check the SageMath migration guide. ↓

fix Use the replacement as documented in SageMath release notes.

gotcha Import paths differ from upstream SageMath. For example, 'sage.categories.all' works but not 'passagemath.categories.all'. Always use 'sage.categories.*'. ↓

fix Use 'from sage.categories import ...' instead of any passagemath prefixed import.

gotcha Python version constraint: requires python >=3.11,<3.15. Not compatible with Python 3.15+ or 3.10 and below. ↓

fix Use a compatible Python interpreter (3.11-3.14).

Imports

Category
wrong
```
from passagemath.categories import Category
```
correct
```
from sage.categories.category import Category
```
passagemath packages keep the sage namespace; direct passagemath import path does not exist.

Rings

wrong

from passerelle.categories import Rings

correct

from sage.categories.rings import Rings

Common typo using old or similar library names.

Quickstart

Basic usage: import from sage namespace and use categories. Requires passagemath-conf and a passagemath environment.

from sage.all import *
from sage.categories.rings import Rings
print(Rings())
print(Category.super_categories_for_sets())