Idiomatic Python Code Review Exercise

idiom.py

# This is an exercise written by Roy Zheng based on the "Writing Idiomatic Python" book.
# Take a look at my blog post here [INSERT] for the full exercise.

class Tank:
    def __init__(self, armor, penetration, armor_type):
      self.armor = armor
      self.penetration = penetration
      self.armor_type = armor_type
      if not (armor_type == 'chobham' or armor_type == 'composite' or armor_type == 'ceramic'):
          raise Exception('Invalid armor type %s' % (armor_type))
      self.tank = "Tank"
          
    def set_name(self, name):
        self.name = name
    
    def vulnerable(self, tank):
        real_armor = self.armor
        if self.armor_type == 'chobham':
            real_armor += 100
        elif self.armor_type == 'composite':
            real_armor += 50
        elif self.armor_type == 'ceramic':
            real_armor += 50
        if real_armor <= tank.penetration: return True
        return False
    
    def swap_armor(self, othertank):
        tmp = othertank.armor
        othertank.armor = self.armor
        self.armor = tmp
        return othertank

    def __repr__(self):
        tmp = self.name.lower()
        tmp = self.name.replace(' ', '-')
        return tmp
      
m1_1 = Tank(600, 670, 'chobham')
m1_2 = Tank(620, 670, 'chobham')
if m1_1.vulnerable(m1_2) is True:
    print 'Vulnerable to self'
m1_1.swap_armor(m1_2)
tanks = []
for i in range(5):
    tanks.append(Tank(400, 400, 'steel'))
index = 0
for tank in tanks:
    tank.set_name('Tank' + str(index) + "_Small")
    index += 1
test = []
index = 0
while index < len(tanks):
    test.append(tanks[i].vulnerable(m1_1))

def test_tank_safe(shooter, test_vehicles=[]):
    at_least_one_safe = False
    for t in test:
        if t:
            at_least_one_safe = True
    if at_least_one_safe:
        print "A tank is safe"
    else:
        print "No tank is safe"

test_tank_safe(m1_1, tanks)