# _*_ coding:utf-8 _*_

##########函数############

#定义函数

def greet_user():

"""显示简单的问候语"""

print("Hello!")

greet_user()

-------------------------------------------

Hello!

-------------------------------------------

#向函数传递信息

def greet_user(username):

"""显示简单的问候语"""

print("Hello, " + username.title() + "!")

greet_user('jesse')

-------------------------------------------

Hello, Jesse!

-------------------------------------------

#传递实参

#位置实参---基于实参的顺序

def describe_pet(animal_type, pet_name):

"""显示宠物信息"""

print(" I have a " + animal_type + ".")

print("My " + animal_type + "'s name is " + pet_name.title() + ".")

describe_pet('hamster', 'harry')

#调用函数多次

describe_pet('dog', 'willie')

-------------------------------------------

I have a hamster.

My hamster's name is Harry.

I have a dog.

My dog's name is Willie.

-------------------------------------------

#关键字实参--传递给函数的名称-值对

describe_pet(animal_type='hamster', pet_name='harry')

#关键字实参和顺序无关紧要

describe_pet(pet_name='harry', animal_type='hamster')

-------------------------------------------

I have a hamster.

My hamster's name is Harry.

I have a hamster.

My hamster's name is Harry.

-------------------------------------------

#默认值---使用默认值时，在形参列表中必须先列出没有默认值的形参，再列出有默认值的形参

def describe_pet(pet_name, animal_type='dog'):

"""显示宠物信息"""

print(" I have a " + animal_type + ".")

print("My " + animal_type + "'s name is " + pet_name.title() + ".")

#等效的函数调用

describe_pet(pet_name ='willie')

describe_pet('willie')

describe_pet(pet_name='harry', animal_type='hamster')

-------------------------------------------

I have a dog.

My dog's name is Willie.

I have a dog.

My dog's name is Willie.

I have a hamster.

My hamster's name is Harry.

-------------------------------------------

#返回值---在函数中，可使用return语句将值返回到调用函数的代码行

def get_formatted_name(first_name,last_name):

"""返回整洁的姓名"""

full_name = first_name + ' ' + last_name

return full_name.title()

musician = get_formatted_name('jimi', 'hendrix')

print(musician)

-------------------------------------------

Jimi Hendrix

-------------------------------------------

#让实参变成可选的

def get_formatted_name(first_name, last_name, middle_name=''):

"""返回整洁的姓名"""

if middle_name:

full_name = first_name + ' ' + middle_name + ' ' + last_name

else:

full_name = first_name + ' ' + last_name

return full_name.title()

musician = get_formatted_name('jimi', 'hendrix')

print(musician)

musician = get_formatted_name('john', 'hooker', 'lee')

print(musician)

-------------------------------------------

Jimi Hendrix

John Lee Hooker

-------------------------------------------

#返回字典---函数可返回任何类型的值，包括列表和字典等较复杂的数据结构

def build_person(first_name, last_name, age=''):

"""返回一个字典，其中包含有关一个人的信息"""

person = {'first': first_name, 'last': last_name}

if age:

person['age'] = age

return person

musician = build_person('jimi', 'hendrix', age=27)

print(musician)

-------------------------------------------

{'first': 'jimi', 'last': 'hendrix', 'age': 27}

-------------------------------------------

#结合使用函数和while循环

def get_formatted_name(first_name,last_name):

"""返回整洁的姓名"""

full_name = first_name + ' ' + last_name

return full_name.title()

#这是一个无限循环

while True:

print(" Please tell me your name:")

print("(enter 'q' at any time to quit)")

f_name = input("First_name: ")

if f_name == 'q':

break

l_name = input("Last_name: ")

if l_name == 'q':

break

formatted_name = get_formatted_name(f_name, l_name)

print(" Hello, " + formatted_name + "!")

-------------------------------------------

Please tell me your name:

(enter 'q' at any time to quit)

First_name: eric

Last_name: matthes

Hello, Eric Matthes!

Please tell me your name:

(enter 'q' at any time to quit)

First_name: q

-------------------------------------------

#传递列表

def greet_users(names):

"""向列表中的每位用户都发出简单的问候"""

for name in names:

msg = "Hello, " + name.title() + "!"

print(msg)

usernames = ['hannah', 'ty', 'margot']

greet_users(usernames)

-------------------------------------------

Hello, Hannah!

Hello, Ty!

Hello, Margot!

-------------------------------------------

#在函数中修改列表

def print_models(unprinted_designs, completed_models):

"""

模拟打印每个设计，直到没有未打印的设计为止

打印每个设计后，都将其移到列表completed_models中

"""

while unprinted_designs:

#从unprinted_designs列表末尾删除一个设计，将其存储到变量current_design中

current_design = unprinted_designs.pop()

#模拟根据设计制作3D打印模型的过程

print("printing model: " + current_design)

completed_models.append(current_design)

def show_completed_models(completed_models):

"""显示打印好的所有模型"""

print(" The following models have been printed:")

for completed_model in completed_models:

print(completed_model)

unprinted_designs= ['iphone case', 'robot pendant', 'dodecahedron']

completed_models = []

print_models(unprinted_designs, completed_models)

show_completed_models(completed_models)

-------------------------------------------

printing model: dodecahedron

printing model: robot pendant

printing model: iphone case

The following models have been printed:

dodecahedron

robot pendant

iphone case

-------------------------------------------

#禁止函数修改列表---切片表示法[:]创建列表的副本

print_models(unprinted_designs[:],completed_models)

#传递任意数量的实参---形参名*toppings中的星号让Python创建一个名为toppings的空元组，并将收到的所有值都封装到这个元组中

#结合使用位置实参和任意数量实参

def make_pizza(size, *toppings):

"""概述要制作的pizza"""

print(" Making a " + str(size) +

"-inch pizza with the following toppings:")

for topping in toppings:

print("-" + topping)

make_pizza(16, 'pepperoni')

make_pizza(12, 'mushrooms', 'green peppers', 'extra cheese')

-------------------------------------------

Making a 16-inch pizza with the following toppings:

-pepperoni

Making a 12-inch pizza with the following toppings:

-mushrooms

-green peppers

-extra cheese

-------------------------------------------

#使用任意数量的关键字实参

def build_profile(first, last, **user_info):

"""创建一个字典，其中包含我们知道的有关用户的一切"""

profile = {}

profile['first_name'] = first

profile['last_name'] = last

for key, value in user_info.items():

profile[key] = value

return profile

user_profile = build_profile('albert', 'einstein', location='princeton', field='physics')

print(user_profile)

-------------------------------------------

{'first_name': 'albert', 'last_name': 'einstein', 'location': 'princeton', 'field': 'physics'}

-------------------------------------------

#将函数存储在模块中

import pizza

pizza.make_pizza(16, 'pepperoni')

pizza.make_pizza(12, 'mushrooms', 'green peppers', 'extra cheese')

#导入特定的函数

from pizza import make_pizza

make_pizza(16, 'pepperoni')

make_pizza(12, 'mushrooms', 'green peppers', 'extra cheese')

#使用as给函数指定别名

from pizza import make_pizza as mp

mp(16, 'pepperoni')

mp(12, 'mushrooms', 'green peppers', 'extra cheese')

#使用as给模块指定别名

import pizza as p

p.make_pizza(16, 'pepperoni')

p.make_pizza(12, 'mushrooms', 'green peppers', 'extra cheese')

#导入模块中的所有函数

from pizza import *

make_pizza(16, 'pepperoni')

make_pizza(12, 'mushrooms', 'green peppers', 'extra cheese')

-------------------------------------------

Making a 16-inch pizza with the following toppings:

-pepperoni

Making a 12-inch pizza with the following toppings:

-mushrooms

-green peppers

-extra cheese

-------------------------------------------