ENH: use oldest-supported-numpy in pyproject.toml

[henryiii]

Is your feature request related to a problem?

Currently using Pandas on Python 3.10 RC 1 gets the wrong version of numpy (1.19) and builds the wheel manually, instead of getting the first wheel for NumPy + Python 3.10 (1.21).

Describe the solution you'd like

This problem has already been solved by https://github.com/scipy/oldest-supported-numpy/blob/master/setup.cfg - by using SciPy (the org, not the package)'s oldest-supported-numpy, you get a thorough and up-to-date listing of the oldest supported numpy's for compiling. You can further control it using normal requirements (such as setting a higher requirement for some version, etc). That's literally all the package does, and is maintained by NumPy maintainers.

API breaking implications

None, just a build improvement.

Describe alternatives you've considered

Otherwise, the contents of https://github.com/scipy/oldest-supported-numpy/blob/master/setup.cfg should be placed in pyproject.toml and maintained for each new Python release - 3.10 is currently missing.

Additional context

Before:

    # Numpy requirements for different OS/architectures
    # Copied from https://github.com/scipy/scipy/blob/master/pyproject.toml (which is also licensed under BSD)
    "numpy==1.17.3; python_version=='3.7' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
    "numpy==1.18.3; python_version=='3.8' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
    "numpy==1.19.3; python_version>='3.9' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
    # Aarch64(Python 3.9 requirements are the same as AMD64)
    "numpy==1.19.2; python_version=='3.7' and platform_machine=='aarch64'",
    "numpy==1.19.2; python_version=='3.8' and platform_machine=='aarch64'",
    # Darwin Arm64
    "numpy>=1.20.0; python_version=='3.8' and platform_machine=='arm64' and platform_system=='Darwin'",
    "numpy>=1.20.0; python_version=='3.9' and platform_machine=='arm64' and platform_system=='Darwin'"

After:

    "oldest-supported-numpy"

(Optionally pinned if you want)

[jreback]

we already do this - i suppose it needs updating for 3.10

[TomAugspurger]

I think the proposal is to replace

pandas/pyproject.toml

Lines 8 to 19 in 5410fb7

	# Numpy requirements for different OS/architectures
	# Copied from https://github.com/scipy/scipy/blob/master/pyproject.toml (which is also licensed under BSD)
	"numpy==1.17.3; python_version=='3.7' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
	"numpy==1.18.3; python_version=='3.8' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
	"numpy==1.19.3; python_version>='3.9' and (platform_machine!='arm64' or platform_system!='Darwin') and platform_machine!='aarch64'",
	# Aarch64(Python 3.9 requirements are the same as AMD64)
	"numpy==1.19.2; python_version=='3.7' and platform_machine=='aarch64'",
	"numpy==1.19.2; python_version=='3.8' and platform_machine=='aarch64'",
	# Darwin Arm64
	"numpy>=1.20.0; python_version=='3.8' and platform_machine=='arm64' and platform_system=='Darwin'",
	"numpy>=1.20.0; python_version=='3.9' and platform_machine=='arm64' and platform_system=='Darwin'"
	]

with just "oldest-supported-numpy", which will keep things up to date for us. That sounds great to me.

[lithomas1]

Duplicate of #40307.

[henryiii]

Duplicate of #40307.

I searched for the string oldest-supported-numpy before opening and didn't see anything, guess because it was in a link?

I think the proposal is to replace

Yes, it was.

we already do this - i suppose it needs updating for 3.10

That was the point (and this is something in this issue not in the issue from 6 months ago), the current list needs updating, but instead of continually updating it, it's better to just take oldest-supported-numpy.