函数章节练习_1

今天计划没完成，下周抽空完成函数章节的练习

print('-'*10,'Introducing Python_CN_Bill Lubanovic_Python语言及其应用','-'*10)

print('-'*10,'定义并调用一个空函数','-'*10)
def do_nothing():
    pass                #pass表名函数没有做任何事情，与这一页留空白同样的作用
do_nothing()            #调用函数
print(do_nothing())     #显示调用函数的内容

print('-'*10,'定义一个无参数，但打印输出一个单词的函数','-'*10)
def make_a_sound():
    print('quack')
make_a_sound()

print('-'*10,'定义一个无参数，但返回值的函数','-'*10)
def agree():
    return True
print(agree())

def agree_2():
    return print(True)
agree_2()

if agree():
    print('Splendid!')
else:
    print('That was unexpected.')

print('-'*10,'引入参数的函数','-'*10)
def echo(anything):
    return anything + ' ' + anything
echo('Rumplestiltskin')
print(echo('Rumplestiltskin'))

print('-'*10,'调用带参数的函数+If','-'*10)
def commentary(color):
    if color == 'red':
        return "It's a tomato"
    elif color == "green":
        return "It's a green pepper"
    elif color == "bee purple":
        return "I don't know that it is,but only bees can see it"
    else:
        return "I've never heard of the color" + color + "."
comment = commentary('blue')
print(comment)

print('-'*10,'有用的None','-'*10)
thing = None
if thing:
    print("It's some do_nothing")
else:
    print("It's no thing")

print('-'*10,'为了区分None和布尔值False','-'*10)
if thing is None:
    print("It's nothing")
else:
    print("It's something")




print('-'*10,'4.7.1 位置参数','-'*10)
def menu(wine, entree, dessert):
    return {'wine':wine, 'entree':entree, 'dessert':dessert}
print(menu('chardonnay', 'chicker', 'cake'))
print(menu('beef', 'bagel', 'bordeaux'))

print('-'*10,'4.7.2 关键字参数','-'*10)
print('关键字参数 = ', menu(entree='beef', dessert='bagel', wine='bordeaux'))
print(menu('frontenac', dessert='flan', entree='fish'))

print('-'*10,'4.7.3 指定默认参数','-'*10)