Hacktoberfest 2026: los issues que los mantenedores marcaron para octubre, abiertos y aptos para principiantes. Explorar issues de Hacktoberfest

expand_dims(None) raises TypeError although None is its documented default

Abierto
  • ¿Algo no está bien?
#261 0 comentarios 0 reacciones 0 asignados Ver en GitHub

Los mantenedores suelen responder en 1 día

@Doribelove ya está trabajando en esto.

Desde el 21/10/2026.

  • #270 de @Doribelove — abierto

Evaluación

Dificultad
2/5
Tiempo estimado
1-3 horas
Aptitud para principiantes
52/100
Tipo de issue
Error
Claridad
Bastante claro
Estado de actividad
Activo
Stack tecnológico
python
Área
robotics

Línea de trabajo

Start with the expand_dims function in the spatialmath.base module, reading its signature, docstring and the code path that raises TypeError: invalid input type. Reproduce with expand_dims() and expand_dims(None). The issue leaves open whether to return None or remove the default, so confirm the maintainers' choice before editing. Done when the chosen behaviour holds and the existing suite still passes.

Escrito por el modelo de indexación a partir del texto del issue.

Descripción

spatialmath.base.expand_dims declares dim with a default of None and documents it (":param dim: dimensions, defaults to None"), but calling it with that value raises:

>>> from spatialmath.base import expand_dims
>>> expand_dims()
TypeError: invalid input type
>>> expand_dims(None)
TypeError: invalid input type

Found while consolidating how RTB resolves a plot or world extent from several candidate sources, where "not given" is a normal state (RTB cannot rely on the default, so it special-cases None before every call).

Current callers already guard it

Every caller in SMTB tests for None before calling, which is the check the function could do itself:

# graphics.py, plotvol2
if dim is None:
    ax.autoscale(True)
else:
    dims = expand_dims(dim, 2)

The same is true of plotvol3, Animate and the dims argument handling in transforms2d.py.

Suggestion

Return None for None:

def expand_dims(dim: ArrayLike | None = None, nd: int = 2) -> NDArray | None:
    if dim is None:
        return None
    ...
  • None is passed through as "unspecified", and the caller decides what that means (autoscale, no limits, use the next candidate).
  • A default box such as [-1, 1, -1, 1] would be worse: it invents a value the caller did not give, and would make "not given" indistinguishable from "given as 1".
  • A wrong-length vector still raises ValueError, so malformed input still fails loudly.
  • The return type becomes NDArray | None, so strictly typed callers need a None check. The existing call sites already have one.

Alternatively, if raising is intended, the signature and docstring should drop the default so that the argument is required.

Tested

With this change SMTB's own suite is unchanged (342 passed before and after). All four SMTB call sites already guard None. One downstream use, in bdsim's GraphicsBlock handling of scale=, would see an invalid scale=None fail later rather than at construction.

Related: #255 (the getvector/getmatrix converters, same family of "accept the natural input" questions).

Lenguaje dominante
Python
Estrellas
648
Forks
108
Merge medio
9 d 19 h
PR fusionados (30 d)
9

Preparar el entorno

Este proyecto no incluye contenedor de desarrollo, Dockerfile ni guía de contribución, así que la configuración corre por tu cuenta: empieza por su README y consulta nuestra guía para la primera contribución para los pasos generales.

Primeros pasos

  1. Lee el issue completo y luego la guía de contribución del proyecto.
  2. Comenta en el issue que vas a ocuparte — evita que dos personas hagan lo mismo.
  3. Haz un fork del repositorio y trabaja en una rama.
  4. Abre un pull request que haga referencia al número del issue.

Más de rai-opensource/spatialmath-python

Todos los issues de rai-opensource/spatialmath-python

Issues similares

Más issues de Python

Recibe los nuevos issues en tu correo

Un resumen breve de issues de GitHub para principiantes.