TheAlgorithms/Python · error · ValueError

vol_cube() only accepts non-negative values

Error message

vol_cube() only accepts non-negative values

What it means

Raised by vol_cube(side_length) in maths/volume.py when side_length is negative. The cube volume is side_length**3, physically meaningless for negative lengths, so the guard rejects them; 0 is explicitly allowed (returns 0.0) and floats are accepted.

Source

Thrown at maths/volume.py:31

def vol_cube(side_length: float) -> float:
    """
    Calculate the Volume of a Cube.

    >>> vol_cube(1)
    1.0
    >>> vol_cube(3)
    27.0
    >>> vol_cube(0)
    0.0
    >>> vol_cube(1.6)
    4.096000000000001
    >>> vol_cube(-1)
    Traceback (most recent call last):
        ...
    ValueError: vol_cube() only accepts non-negative values
    """
    if side_length < 0:
        raise ValueError("vol_cube() only accepts non-negative values")
    return pow(side_length, 3)


def vol_spherical_cap(height: float, radius: float) -> float:
    """
    Calculate the volume of the spherical cap.

    >>> vol_spherical_cap(1, 2)
    5.235987755982988
    >>> vol_spherical_cap(1.6, 2.6)
    16.621119532592402
    >>> vol_spherical_cap(0, 0)
    0.0
    >>> vol_spherical_cap(-1, 2)
    Traceback (most recent call last):
        ...
    ValueError: vol_spherical_cap() only accepts non-negative values
    >>> vol_spherical_cap(1, -2)

View on GitHub (pinned to f5988cc097)

Solutions

1. Validate measurement sign at ingestion: lengths must be >= 0
2. If the value may be a magnitude error, take abs() only when that is physically justified — otherwise reject the input
3. Pre-check with your own guard: if side < 0: reject before calling

Example fix

// before
v = vol_cube(-1)  # ValueError

// after
v = vol_cube(abs(-1)) if magnitude_only else vol_cube(1)

if side_length < 0:
    raise ValueError(f'invalid cube side {side_length}')
v = vol_cube(side_length)

When it happens

Trigger: Calling vol_cube(-1) with any negative value. There is no type check — strings will fail later with a TypeError from the comparison/pow, not with this message.

Common situations: Geometry inputs parsed from user data or measurements where a minus sign slipped in; symmetric-error propagation (e.g. delta = a - b) producing negative 'lengths'.

Related errors

• vol_spherical_cap() only accepts non-negative values
• surface_area_cube() only accepts non-negative values
• surface_area_cuboid() only accepts non-negative values
• surface_area_sphere() only accepts non-negative values
• surface_area_hemisphere() only accepts non-negative values

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/2a5cc4b82fd59ab5. Report an issue: GitHub.