pyproject.toml

[build-system]
requires = [
    "wheel",
    "setuptools",
    "Cython",  # required for VCS build, optional for released source
    "numpy==1.9.3; python_version=='3.5'",
    "numpy==1.12.1; python_version=='3.6'",
    "numpy==1.13.1; python_version>='3.7'",
]