print("I will now count my chickens:")
print("Hens", 25 + 30 / 6) # py2结果为30
print("Roosters", 100 - 25 * 3 % 4)

print("Now I will count the eggs:")
print(3 + 2 + 1 - 5 + 4 % 2 - 1 / 4 + 6) ＃ py2结果为整数

print("Is it true that 3 + 2 < 5 - 7?")
print(3 + 2 < 5 - 7)

print("What is 3 + 2?", 3 + 2)
print("What is 5 - 7?", 5 - 7)

print("Oh, that's why it's False.")

print("How about some more.")

print("Is it greater?", 5 > -2)
print("Is it greater or equal?", 5 >= -2)
print("Is it less or equal?", 5 <= -2)

x = "There are %d types of people." % 10
binary = "binary"
do_not = "don't"
y = "Those who know %s and those who %s." % (binary, do_not)

print(x)
print(y)

print("I said: %r." % x)
print("I also said: '%s'." % y)

hilarious = False
joke_evaluation = "Isn't that joke so funny?! %r"

print(joke_evaluation % hilarious)

w = "This is the left side of..."
e = "a string with a right side."

print(w + e)

from sys import argv
from os.path import exists

script, from_file, to_file = argv

print("Copying from %s to %s" % (from_file, to_file))

in_file = open(from_file)
indata = in_file.read()

print("The input file is %d bytes long" % len(indata))

print("Does the output file exist? %r" % exists(to_file))
print("Ready, hit RETURN to continue, CTRL-C to abort.")
raw_input()

out_file = open(to_file, 'w')
out_file.write(indata)

print("Alright, all done.")

out_file.close()
in_file.close()

!echo "This is a test file." > test.txt

!cat test.txt

%run ex17.py test.txt new_file.txt

%run ex17.py test.txt new_file.txt

print("Let's practice everything.")
print('You\'d need to know \'bout escapes with \\ that do \n newlines and \t tabs.')

poem = """
\tThe lovely world
with logic so firmly planted
cannot discern \n the needs of love
nor comprehend passion from intuition
and requires an explanation
\n\t\twhere there is none.
"""

print("--------------")
print(poem)
print("--------------")


five = 10 - 2 + 3 - 6
print("This should be five: %s" % five)

def secret_formula(started):
    jelly_beans = started * 500
    jars = jelly_beans / 1000
    crates = jars / 100
    return jelly_beans, jars, crates


start_point = 10000
beans, jars, crates = secret_formula(start_point)

print("With a starting point of: %d" % start_point)
print("We'd have %d beans, %d jars, and %d crates." % (beans, jars, crates))

start_point = start_point / 10

print("We can also do that this way:")
print("We'd have %d beans, %d jars, and %d crates." % secret_formula(start_point))

from sys import exit

def gold_room():
    print("This room is full of gold.  How much do you take?")

    choice = input("> ")
    if "0" in choice or "1" in choice:
        how_much = int(choice)
    else:
        dead("Man, learn to type a number.")

    if how_much < 50:
        print("Nice, you're not greedy, you win!")
        exit(0)
    else:
        dead("You greedy bastard!")


def bear_room():
    print("There is a bear here.")
    print("The bear has a bunch of honey.")
    print("The fat bear is in front of another door.")
    print("How are you going to move the bear?")
    bear_moved = False

    while True:
        choice = input("> ")

        if choice == "take honey":
            dead("The bear looks at you then slaps your face off.")
        elif choice == "taunt bear" and not bear_moved:
            print("The bear has moved from the door. You can go through it now.")
            bear_moved = True
        elif choice == "taunt bear" and bear_moved:
            dead("The bear gets pissed off and chews your leg off.")
        elif choice == "open door" and bear_moved:
            gold_room()
        else:
            print("I got no idea what that means.")


def cthulhu_room():
    print("Here you see the great evil Cthulhu.")
    print("He, it, whatever stares at you and you go insane.")
    print("Do you flee for your life or eat your head?")

    choice = input("> ")

    if "flee" in choice:
        start()
    elif "head" in choice:
        dead("Well that was tasty!")
    else:
        cthulhu_room()


def dead(why):
    print(why, "Good job!")
    exit(0)

def start():
    print("You are in a dark room.")
    print("There is a door to your right and left.")
    print("Which one do you take?")

    choice = input("> ")

    if choice == "left":
        bear_room()
    elif choice == "right":
        cthulhu_room()
    else:
        dead("You stumble around the room until you starve.")


start()

states = {
    'Oregon': 'OR',
    'Florida': 'FL',
    'California': 'CA',
    'New York': 'NY',
    'Michigan': 'MI'
}

cities = {
    'CA': 'San Francisco',
    'MI': 'Detroit',
    'FL': 'Jacksonville'
}

cities['NY'] = 'New York'
cities['OR'] = 'Portland'

print('-' * 10)
print("NY State has: ", cities['NY'])
print("OR State has: ", cities['OR'])

print('-' * 10)
print("Michigan's abbreviation is: ", states['Michigan'])
print("Florida's abbreviation is: ", states['Florida'])

print('-' * 10)
print("Michigan has: ", cities[states['Michigan']])
print("Florida has: ", cities[states['Florida']])

print('-' * 10)
for state, abbrev in states.items():
    print("%s is abbreviated %s" % (state, abbrev))

print('-' * 10)
for abbrev, city in cities.items():
    print("%s has the city %s" % (abbrev, city))

print('-' * 10)
for state, abbrev in states.items():
    print("%s state is abbreviated %s and has city %s" % (
        state, abbrev, cities[abbrev]))

print('-' * 10)
state = states.get('Texas')

if not state:
    print("Sorry, no Texas.")

city = cities.get('TX', 'Does Not Exist')
print("The city for the state 'TX' is: %s" % city)

class Animal(object): 
    pass

class Dog(Animal):
    def __init__(self, name):
        self.name = name

class Cat(Animal):
    def __init__(self, name):
        self.name = name

class Person(object):
    def __init__(self, name):
        self.name = name
        self.pet = None

class Employee(Person):
    def __init__(self, name, salary):
        super(Employee, self).__init__(name) # 初始化name为父类的name
        self.salary = salary

class Fish(object):
    pass

class Salmon(Fish):
    pass

class Halibut(Fish):
    pass


rover = Dog("Rover")
satan = Cat("Satan")
mary = Person("Mary")
mary.pet = satan
frank = Employee("Frank", 120000)
frank.pet = rover
flipper = Fish()
crouse = Salmon()
harry = Halibut()