#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)