men = [
    "Grouper",
    "Trout",
    "Ray",
    "Mackerel",
    "Snapper",
    "Bass"
    ]

# Rule functions return a boolean indicating if the rule denies the organisation.
def rule1(org):
    """Grouper won't be an officer unless Snapper is President"""

    if "Grouper" in org and org.pres != "Snapper":
        return False
    return True

def rule2(org):
    """Trout won't serve if he outranks Ray"""

    # Assume that rank is pres > vp > sec.
    # Also that if Ray does not serve, Trout is happy to serve

    if "Trout" in org and "Ray" in org and org["Trout"] > org["Ray"]:
        return False
    return True

def rule3(org):
    """Trout won't serve with Bass under any conditions"""

    if "Trout" in org and "Bass" in org:
        return False
    return True

def rule4(org):
    """Ray won't serve with both Snapper & Bass"""

    if "Ray" in org and "Snapper" in org and "Bass" in org:
        return False
    return True

def rule5(org):
    """Ray won't serve if Bass is President or Trout is secretary"""

    if "Ray" in org and (org.pres == "Bass" or org.sec == "Trout"):
        return False
    return True

def rule6(org):
    """Mackerel won't serve with Ray or Snapper unless he outranks him"""

    # Assume that Mackerel wants > (Ray | Snapper)

    if "Mackerel" in org and ("Ray" in org and org["Mackerel"] < org["Ray"]
            or "Snapper" in org and org["Mackerel"] < org["Snapper"]):
        return False
    return True

def rule7(org):
    """Snapper won't be Vice-President"""

    if org.vp == "Snapper":
        return False
    return True

def rule8(org):
    """Snapper won't be secretary if Mackerel is an officer"""

    if org.sec == "Snapper" and "Mackerel" in org:
        return False
    return True

def rule9(org):
    """Snapper won't serve with Grouper unless Bass serves too"""

    if "Snapper" in org and "Grouper" in org and "Bass" not in org:
        return False
    return True

def rule10(org):
    """Bass won't serve unless either he or Ray is President"""

    if "Bass" in org and org.pres != "Bass" and org.pres != "Ray":
        return False
    return True


rules = [
    rule1, rule2, rule3, rule4, rule5,
    rule6, rule7, rule8, rule9, rule10
    ]


class Organisation(object):
    def __init__(self, pres, vp, sec):
        self.pres = pres
        self.vp = vp
        self.sec = sec

    def __contains__(self, item):
        return (self.pres == item or self.vp == item or self.sec == item)

    def __getitem__(self, key):
        if self.pres == key:
            return 3
        elif self.vp == key:
            return 2
        elif self.sec == key:
            return 1
        else:
            raise IndexError("Organisation does not contain %s" % key)

    def __str__(self):
        return "pres: %s, vp: %s, sec: %s" % (self.pres, self.vp, self.sec)


# Generate list of all possible organisations
orgs = []
pres_choices = list(men)
for pres in pres_choices:
    vp_choices = list(pres_choices)
    vp_choices.remove(pres)

    for vp in vp_choices:
        sec_choices = list(vp_choices)
        sec_choices.remove(vp)

        for sec in sec_choices:
            org = Organisation(pres, vp, sec)
            orgs.append(org)

# Check the list against the rules and chuck out all that don't apply
for i, rulefunc in enumerate(rules):
    print; print "Evaluating rule %d\n'%s':" % (i + 1, rulefunc.__doc__)

    remaining_orgs = []
    for org in orgs:
        if rulefunc(org):
            remaining_orgs.append(org)
        else:
            print "  Disallows " + str(org)

    orgs = remaining_orgs

print; print "Organisations which pass all rules:"
for org in orgs:
    print org