Guibs 的 Python学习_ 函数

# 函数# 函数是带有名字的代码块, 用于完成具体的工作# 定义函数 greet_userdef greet_user():
 # 函数体
 print("Hello")# 调用函数 greet_usergreet_user()# 向函数传递信息def greet_user(username): # username 是一个形参
 print("Hello " + username)
greet_user(username='Guibs') # Guibs 是一个实参greet_user('Guibs')# 带关键字传递实参# 可以不用考虑实参传递的顺序def greet_user(username1, username2):
 print("Hello " + username1 + " and " + username2)
greet_user(username2='Guibs', username1='Guibs82')# 参数默认值# 若不传递参数则调用默认值# 含有默认值的参数必须放在后面
def greet_user_with_default_name(username1, username2='Guibs82'):
 print("Hello " + username1 + " and " + username2)# 若未传递足够参数, 则按位置进行参数传递greet_user_with_default_name('G')# 返回值
def get_formatted_name(first_name, last_name, middle_name = ""):
 if middle_name:
 full_name = first_name + " " + middle_name + " " + last_name else:
 full_name = first_name + " " + last_name return full_name.title()
my_name = get_formatted_name("guibs", "g")
print("My name is " + my_name)

my_name = get_formatted_name("guibs", 'g', '82')
print("My name is " + my_name)# 返回字典def build_person(first_name, last_name, age=''):
 '''返回一个字典, 包含有关一个人的信息'''
 person = { 'first': first_name.title(), 'last': last_name.title(),
 } if age:
 person['age'] = age return person
print(build_person('g', 'ghost', 22))# 传递列表names = ['guibs', 'ghostg', 'rio_G']def greet_users(names):
 for name in names:
 print("Hello " + name.title())
greet_users(names=names)# 在函数中修改列表# 将列表传递给函数后, 函数可以对其进行永久性修改unprinted_designs = ['iphone case', 'ipad case', 'mac case']
printed_designs = []def print_designs(unprinted_designs, printed_designs):
 while unprinted_designs:
 current_design = unprinted_designs.pop()
 print("准备打印: " + current_design)
 printed_designs.append(current_design)
 print("打印完毕: " + current_design)
 print("全部作品打印完毕")
print_designs(unprinted_designs=unprinted_designs, printed_designs=printed_designs)def show_printed_designs(printed_designs):
 print("打印完毕的作品: ") for printed_design in printed_designs:
 print(printed_design)
show_printed_designs(printed_designs)# 禁止函数修改列表# 采用切片的形式, 复制传入函数的列表
unprinted_designs = ['iphone case', 'ipad case', 'mac case', 'apple watch case']
printed_designs = []
print_designs(unprinted_designs[:], printed_designs)
print(unprinted_designs) # 此时, 原列表未被修改# 传递任意数量的参数# [*param_name]# 此时, Python 将参数封装至一个元组def print_username(*username):
 print(username)
print_username("Guibs")
print_username("Guibs", 'GhostG')# 使用任意数量的关键字形参# [**param_names]def set_hobbies(name, **hobbies):
 my_hobbies = {}
 my_hobbies['name'] = name for key, value in hobbies.items():
 my_hobbies[key] = value return my_hobbies

print(set_hobbies(name="Guibs", hobby_1='Swift', hobby_2='Python'))# 注意: 在 import 时, 若不使用系统中的解释器, 而是用自己创建的, 则报错
# 导入存储在模块中的函数
# 导入整个模块import pizza
pizza.make_pizza(12, 'mushrooms', 'extra cheese')# 使用 as 给模块指定别名import pizza as p
p.make_pizza(12, 'mushrooms', 'lots of cheese')# 导入特定的函数# from module_name import function_name_0, function_name_1, ...
# 这种语法可以无需使用 .from pizza import make_pizza
make_pizza(12, 'mushrooms', 'more cheese')# 使用 as 给函数指定别名from pizza import make_pizza as buy_pizza
buy_pizza(12, 'mushrooms', 'a lot of cheese')# 导入模块中的所有函数# [*]from pizza import *
get_price()

运行上方代码另需新建 pizza.py

def make_pizza(size, *toppings):
 '''概述要制作的披萨'''
 print("做一个尺寸为: " + str(size) + ", 包含: ") for topping in toppings:
 print("- " + topping)
 print("的披萨")def get_price():
 print("The price is 20")