build.py

import os
import sys


from distutils.core import Extension

from distutils.errors import CCompilerError, DistutilsExecError, DistutilsPlatformError
from distutils.command.build_ext import build_ext


# C Extensions
with_extensions = os.getenv("PENDULUM_EXTENSIONS", None)

if with_extensions == "1" or with_extensions is None:
    with_extensions = True

if with_extensions == "0" or hasattr(sys, "pypy_version_info"):
    with_extensions = False

extensions = []
if with_extensions:
    extensions = [
        Extension("pendulum._extensions._helpers", ["pendulum/_extensions/_helpers.c"]),
        Extension("pendulum.parsing._iso8601", ["pendulum/parsing/_iso8601.c"]),
    ]


class BuildFailed(Exception):

    pass


class ExtBuilder(build_ext):
    # This class allows C extension building to fail.

    def run(self):
        try:
            build_ext.run(self)
        except (DistutilsPlatformError, FileNotFoundError):
            print("************************************************************")
            print("Cannot compile C accelerator module, use pure python version")
            print("************************************************************")

    def build_extension(self, ext):
        try:
            build_ext.build_extension(self, ext)
        except (CCompilerError, DistutilsExecError, DistutilsPlatformError, ValueError):
            print("************************************************************")
            print("Cannot compile C accelerator module, use pure python version")
            print("************************************************************")


def build(setup_kwargs):
    """
    This function is mandatory in order to build the extensions.
    """
    setup_kwargs.update(
        {"ext_modules": extensions, "cmdclass": {"build_ext": ExtBuilder}}
    )