Use proper PEP 508 environment marker to install colorama on Windows only

[niander]

Issue #256

Using proper PEP 508 environment marker to install colorama on Windows only.

[jiasli]

Indeed, after decompressing https://files.pythonhosted.org/packages/bf/9e/6378bc3d04592cd3692dd50f829c6678fae69052fda048a7981657c17489/knack-0.9.0-py3-none-any.whl, knack-0.9.0.dist-info/METADATA contains:

Requires-Dist: argcomplete
Requires-Dist: jmespath
Requires-Dist: pygments
Requires-Dist: pyyaml
Requires-Dist: tabulate

[jiasli]

I am actually wondering which one is the best:

• os_name
• sys_platform
• platform_system

portalocker is one dependency of Azure CLI and it uses:

https://github.com/WoLpH/portalocker/blob/00cffcb1831208691d3bf6850df4768989a0bd4c/setup.py#L133

            'pywin32>=226; platform_system == "Windows"',

[niander]

I have seen several projects to use platform_system == "Windows" before, but none to use sys_platform. I don't think it matters but maybe we should use platform_system because it is more commonly used?

[niander]

Oh, I see this has already been merged so I guess it doesn't matter. But.. Would ever be the case sys_platform would be something else than win32 in a Windows? Like win64?

[jiasli]

Would ever be the case sys_platform would be something else than win32 in a Windows? Like win64?

I don't think so. I am running 64-bit Python on 64-bit Windows:

> python -c "import sys; print(sys.platform)"
win32

https://docs.python.org/3/library/sys.html#sys.platform only mentions win32 too.

[niander]

When will this be released?