第13天：Python 函数的参数

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             raise ValueError('invalid user response')        print(reminder)        # 我们可以如下进行调用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, 'Please, yes or no!')

def f(a, l=[]):    l.append(a)    return l    # 此时调用函数print(f(1))print(f(2))print(f(3))
# 返回值# [1]# [1, 2]# [1, 2, 3]

def f(a, l=None):    if l is None:        l = []    l.append(a)    return l
# 再次调用函数print(f(1))print(f(2))print(f(3))
# 返回值# [1]# [2]# [3]

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])        # 函数调用variable_fun("xiaoming",             "hello xiaoming", "nice to meet you!",            mother="xiaoma",            father="xiaoba",            son="see you")            # 输出结果first arg:  xiaoming ...----------------------------------------hello nice to meet you!----------------------------------------mother : xiaomafather : xiaobason : see you

list01 = ["hello xiaoming", "nice to meet you!"]dict01 = {'mother': 'xiaoma', 'father': 'xiaoba', 'son': 'see you'}variable_fun("xiaoming", *list01, **dict01)

# 借用官网例子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, "!")
# 函数调用  key_fun(1000)                                          # 1 positional argumentkey_fun(voltage=1000)                                  # 1 keyword argumentkey_fun(voltage=1000000, action='VOOOOOM')             # 2 keyword argumentskey_fun(action='VOOOOOM', voltage=1000000)             # 2 keyword argumentskey_fun('a million', 'bereft of life', 'jump')         # 3 positional argumentskey_fun('a thousand', state='pushing up the daisies')  # 1 positional, 1 keyword

# TypeError: key_fun() got multiple values for argument 'voltage'key_fun(100, voltage=1000)                             # error