"""
>>> bus1 = HauntedBus(['Alice', 'Bill'])
>>> bus1.passengers
['Alice', 'Bill']
>>> bus1.pick('Charlie')
>>> bus1.drop('Alice')
>>> bus1.passengers
['Bill', 'Charlie']
>>> bus2 = HauntedBus()
>>> bus2.pick('Carrie')
>>> bus2.passengers
['Carrie']
>>> bus3 = HauntedBus()
>>> bus3.passengers
['Carrie']
>>> bus3.pick('Dave')
>>> bus2.passengers
['Carrie', 'Dave']
>>> bus2.passengers is bus3.passengers
True
>>> bus1.passengers
['Bill', 'Charlie']
>>> dir(HauntedBus.__init__) # doctest: +ELLIPSIS
['__annotations__', '__call__', ..., '__defaults__', ...]
>>> HauntedBus.__init__.__defaults__
(['Carrie', 'Dave'],)
>>> HauntedBus.__init__.__defaults__[0] is bus2.passengers
True
"""
# BEGIN HAUNTED_BUS_CLASS
class HauntedBus:
"""A bus model haunted by ghost passengers"""
def __init__(self, passengers=[]): # <1>
self.passengers = passengers # <2>
def pick(self, name):
self.passengers.append(name) # <3>
def drop(self, name):
self.passengers.remove(name)
# END HAUNTED_BUS_CLASS
