def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def test_ccode_constants_other():
    assert ccode(2*GoldenRatio) == "double const GoldenRatio = 1.61803398874989;\n2*GoldenRatio"
    assert ccode(
        2*Catalan) == "double const Catalan = 0.915965594177219;\n2*Catalan"
    assert ccode(2*EulerGamma) == "double const EulerGamma = 0.577215664901533;\n2*EulerGamma"