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 display(self, callingWindow, srcContext, mainItem):
        if srcContext not in ("marketItemGroup", "marketItemMisc") or self.mainFrame.getActiveFit() is None:
            return False

        if mainItem is None:
            return False

        for attr in ("emDamage", "thermalDamage", "explosiveDamage", "kineticDamage"):
            if mainItem.getAttribute(attr) is not None:
                return True

        return False