#不定长参数，这里prams是一个元组集合

def print_params(*prams):

for e in prams:

print(e)

print(prams) #输出('xxx', (1, 2, 3), 'hello')

print_params("xxx", (1,2,3), "hello")

#关键字参数，使用参数名提供的参数，主要用于明确每个参数的作用，例如

def hello_print(greeting = "hello", name = "world"):

print('%s %s' % (greeting, name) )

hello_print() #输出hello world

hello_print("hello", "sysnap") #输出hello sysnap

hello_print(name = "hello", greeting = "sysnap") #输出sysnap hello

#不定长参数 + 关键字参数

#print_params(name = "hello") 这样会出错，如何避免呢，需要**

def print_params_2(*params1, **params):

for e in params1:

print(e)

print(params1) #输出(1, 2, 3)

print(params) #输出{'name': 'sysnap'},是一个字典

print_params_2(1,2,3, name = "sysnap")

print_params_2(1,2,3, name = "sysnap", age = 10)

#(1, 2, 3)

#{'age': 10, 'name': 'sysnap'}

#反转过程

def add(x, y):

return x + y

print(add(10,20)) #输出30，也可以下面的调用

params = (10, 20)

print(add(*params))

def print_str(name, age):

print("name is: %s, age is %d" % (name, age))

del params

params = {"name":"sysnap", "age":10}

print_str(**params)