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 opengl_lamp_buttons(column, lamp):
    split = column.row()

    split.prop(lamp, "use", text="", icon='OUTLINER_OB_LAMP' if lamp.use else 'LAMP_DATA')

    col = split.column()
    col.active = lamp.use
    row = col.row()
    row.label(text="Diffuse:")
    row.prop(lamp, "diffuse_color", text="")
    row = col.row()
    row.label(text="Specular:")
    row.prop(lamp, "specular_color", text="")

    col = split.column()
    col.active = lamp.use
    col.prop(lamp, "direction", text="")