[BUG]: Installation process is broken

[gsuberland]

Description

The installation steps simply say to run pip install colour-science. This installs 0.3.16, which gives the following error:

>>> import colour
Traceback (most recent call last):
  File "<python-input-0>", line 1, in <module>
    import colour
  File "C:\Users\Graham\AppData\Local\Programs\Python\Python314\Lib\site-packages\colour\__init__.py", line 52, in <module>
    from .utilities.deprecation import ModuleAPI, build_API_changes
  File "C:\Users\Graham\AppData\Local\Programs\Python\Python314\Lib\site-packages\colour\utilities\__init__.py", line 9, in <module>
    from .common import (
    ...<9 lines>...
        from_range_int, copy_definition)
  File "C:\Users\Graham\AppData\Local\Programs\Python\Python314\Lib\site-packages\colour\utilities\common.py", line 33, in <module>
    from colour.constants import INTEGER_THRESHOLD, DEFAULT_FLOAT_DTYPE
  File "C:\Users\Graham\AppData\Local\Programs\Python\Python314\Lib\site-packages\colour\constants\__init__.py", line 8, in <module>
    from .common import (FLOATING_POINT_NUMBER_PATTERN, INTEGER_THRESHOLD, EPSILON,
                         DEFAULT_FLOAT_DTYPE, DEFAULT_INT_DTYPE)
  File "C:\Users\Graham\AppData\Local\Programs\Python\Python314\Lib\site-packages\colour\constants\common.py", line 46, in <module>
    EPSILON = np.finfo(np.float_).eps
                       ^^^^^^^^^
  File "C:\Users\Graham\AppData\Local\Programs\Python\Python314\Lib\site-packages\numpy\__init__.py", line 794, in __getattr__
    raise AttributeError(
    ...<3 lines>...
    )
AttributeError: `np.float_` was removed in the NumPy 2.0 release. Use `np.float64` instead.

This seems to have been resolved in #1121, but since a regular release hasn't been done since then it's still causing problems.

Attempting to install 0.4.6 explicitly in Python 3.14.0 fails:

py -m pip install --user --pre --upgrade "colour-science>=0.4.6"
ERROR: Ignored the following versions that require a different python version: 0.4.0 Requires-Python >=3.8,<3.11; 0.4.1 Requires-Python >=3.8,<3.11; 0.4.2 Requires-Python >=3.9,<3.12; 0.4.3 Requires-Python >=3.9,<3.12; 0.4.4 Requires-Python >=3.9,<3.13; 0.4.5 Requires-Python >=3.10,<3.14; 0.4.6 Requires-Python >=3.10,<3.14
ERROR: Could not find a version that satisfies the requirement colour-science>=0.4.6 (from versions: 0.3.0, 0.3.1, 0.3.2, 0.3.3, 0.3.4, 0.3.5, 0.3.6, 0.3.7, 0.3.8, 0.3.9, 0.3.10, 0.3.11, 0.3.12, 0.3.13, 0.3.14, 0.3.15, 0.3.16)
ERROR: No matching distribution found for colour-science>=0.4.6

I installed on Python 3.11.3 using python -m pip install --user --pre --upgrade "colour-science>=0.4.6". However, trying to import now brings a new error:

>>> import colour
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Graham\AppData\Roaming\Python\Python311\site-packages\colour\__init__.py", line 72, in <module>
    from colour import plotting  # noqa: F401
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Graham\AppData\Roaming\Python\Python311\site-packages\colour\plotting\__init__.py", line 1, in <module>
    from colour.utilities import is_matplotlib_installed
  File "C:\Users\Graham\AppData\Roaming\Python\Python311\site-packages\colour\utilities\__init__.py", line 132, in <module>
    from .metrics import metric_mse, metric_psnr
  File "C:\Users\Graham\AppData\Roaming\Python\Python311\site-packages\colour\utilities\metrics.py", line 23, in <module>
    from colour.algebra import sdiv, sdiv_mode
  File "C:\Users\Graham\AppData\Roaming\Python\Python311\site-packages\colour\algebra\__init__.py", line 32, in <module>
    from .interpolation import (
  File "C:\Users\Graham\AppData\Roaming\Python\Python311\site-packages\colour\algebra\interpolation.py", line 67, in <module>
    import scipy.interpolate
  File "C:\Python311\Lib\site-packages\scipy\interpolate\__init__.py", line 192, in <module>
    from ._interpolate import *
  File "C:\Python311\Lib\site-packages\scipy\interpolate\_interpolate.py", line 8, in <module>
    import scipy.special as spec
  File "C:\Python311\Lib\site-packages\scipy\special\__init__.py", line 790, in <module>
    from . import _basic
  File "C:\Python311\Lib\site-packages\scipy\special\_basic.py", line 22, in <module>
    from ._multiufuncs import (assoc_legendre_p_all,
  File "C:\Python311\Lib\site-packages\scipy\special\_multiufuncs.py", line 142, in <module>
    sph_legendre_p = MultiUFunc(
                     ^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\scipy\special\_multiufuncs.py", line 41, in __init__
    raise ValueError("All ufuncs must have type `numpy.ufunc`."
ValueError: All ufuncs must have type `numpy.ufunc`. Received (<ufunc 'sph_legendre_p'>, <ufunc 'sph_legendre_p'>, <ufunc 'sph_legendre_p'>)
>>>

Code for Reproduction

Exception Message

Environment Information

Windows 10 x64, Python 3.11.3 and Python 3.14.0

[KelSolaar]

Hi @gsuberland,

We have released plenty of versions since 0.3.16:

• v0.3.16
• v0.4.0
• v0.4.1
• v0.4.2
• v0.4.3
• v0.4.4
• v0.4.5
• v0.4.6

The issue you see is that we have not released a version that support Python 3.14 yet. Two solutions:

• You install with uv / pyenv for Python 3.13
• You install from the develop branch that has Python 3.14 support since this weekend!

Alternatively, you wait a bit as we will release 0.4.7 in coming weeks :)

Cheers,

[gsuberland]

The installation guide shows Python 3.11.3 as being in the supported version range. As noted, trying to install with pip on 3.11.3 produces an error when trying to actually use the library.

I dug a bit further and I think your package dependency info for numpy is incorrect. Currently it is spec'd for numpy >= 1.24, < 3, and indeed I had 1.26.4 installed:

Requirement already satisfied: numpy<3,>=1.24 in c:\python311\lib\site-packages (from colour-science>=0.4.6) (1.26.4)

This should, then, work. But it doesn't. Under the suspicion that the version was too old, I manually upgraded numpy to something in the 2.x range:

python -m pip install --user --upgrade "numpy>2,<3"
Collecting numpy<3,>2
  Downloading numpy-2.3.5-cp311-cp311-win_amd64.whl.metadata (60 kB)
Downloading numpy-2.3.5-cp311-cp311-win_amd64.whl (13.1 MB)

This now works correctly.

[KelSolaar]

Mmmh, I won't have time to dig with your Python 3.11 specific issue but it is worth noting that we have been testing from 3.10 to 3.13 for a year and this on Linux, macOs and Windows.

[gsuberland]

I think the reason you've not seen it in testing is that if you install on a fresh box then pip will automatically pull in numpy 2.x to satisfy the dependency, which works fine. But if you previously installed a different package that had a dependency on numpy 1.x, such as in my case where I had 1.26.4 installed, then the numpy<3,>=1.24 constrained on colour-science is already satisfied. But something about numpy.ufunc in 1.x is different to in 2.x, and colour-science no longer works with that older behaviour.

You should be able to test this quite easily: explicitly install numpy 1.26.4, then install colour-science. It'll install without any dependency complaints, but import colour will fail with the numpy.ufunc stack trace as I showed above.

The solution here is either to bump your numpy dependency to numpy<3,>=2, since 1.x no longer works, or bisect the 1.x versions to find the change in numpy.ufunc behaviour that causes the import failure and adjust the version dependency range based on that.

[KelSolaar]

Ah right I see, yes that makes sense, technically, we should not be supporting Numpy 2.0 anymore, we are following Scientific Python SPEC-0 and Numpy 2.0 support will be dropped when 0.4.7 is released. The issue is that we have a much slower release cadence than other NumFOCUS projects.