# -*-coding:UTF-8-*-

# 默认值函数测试

def def_param_fun(prompt, retries=4, reminder='Please try again!'):

while True:

ok = input(prompt)

if ok in ('y', 'ye', 'yes'):

return True

if ok in ('n', 'no', 'nop', 'nope'):

return False

retries = retries - 1

if retries < 0:

raise ValueError('invalid user response')

print(reminder)

# 函数调用

# def_param_fun('Do you really want to quit?')

# def_param_fun('Do you really want to quit?', 2)

# def_param_fun('Do you really want to quit?', 2, 'Come on, only yes or no!')

# 默认值只会执行一次。这条规则在默认值为可变对象（列表、字典以及大多数类实例）时很重要

def f(a, l=[]):

l.append(a)

return l

# def f(a, l=None):

# if l is None:

# l = []

# l.append(a)

# return l

# print(f(1))

# print(f(2))

# print(f(3))

# 可变参数

def variable_fun(kind, *arguments, **keywords):

print("friend : ", kind, ";")

print("-" * 40)

for arg in arguments:

print(arg)

print("-" * 40)

for kw in keywords:

print(kw, ":", keywords[kw])

# 调用1

# variable_fun("xiaoming",

# "hello xiaoming", "nice to meet you!",

# mother="xiaoma",

# father="xiaoba",

# son="see you")

# 调用2

# list01 = ["hello xiaoming", "nice to meet you!"]

# dict01 = {'mother': 'xiaoma', 'father': 'xiaoba', 'son': 'see you'}

# variable_fun("xiaoming", *list01, **dict01)

# 关键字参数 以下函数接受一个必需的参数（voltage）和三个可选的参数（state, action，和 type）

def key_fun(voltage, state='a stiff', action='voom', type='Norwegian Blue'):

print("-- This key_fun wouldn't", action, end=' ')

print("if you put", voltage, "volts through it.")

print("-- Lovely plumage, the", type)

print("-- It's", state, "!")

key_fun(1000) # 1 positional argument

key_fun(voltage=1000) # 1 keyword argument

key_fun(voltage=1000000, action='VOOOOOM') # 2 keyword arguments

key_fun(action='VOOOOOM', voltage=1000000) # 2 keyword arguments

key_fun('a million', 'bereft of life', 'jump') # 3 positional arguments

key_fun('a thousand', state='pushing up the daisies') # 1 positional, 1 keyword

# 重复传入参数，不允许

# TypeError: key_fun() got multiple values for argument 'voltage'

key_fun(100, voltage=1000) # error