# 定义方法
def empty_function():
    pass
print('invoke empty_function() result:{}'.format(empty_function()))

def get_result_funtion(a):
    return a>0
print('invoke get_result_funtion(-1) result:{}'.format(get_result_funtion(-1)))


# 关键字参数
def get_max_param(a:int,b:int,c:int):
    return (a,b,c)
print('invoke get_max_param(a=10,c=1,b=122) result:{}'.format(get_max_param(a=10,c=1,b=122)))

# 任意参数

def concat_str(*parms):
    return parms
print('invoke concat_str("I"," love ","Li","Rui","Xin") result:{}'.format(concat_str("I"," love ","Li","Rui","Xin")))


# lambda 函数
'''
lambda arguments : expression
'''
lambdaX = lambda a: a is str
a = 1
print('invoke lambdaX: {} is str = {}'.format( a,lambdaX(a)))

lambdaSum = lambda a,b: a+b
a,b= 10,20
print('invoke lambdaSum: {}+{}={}'.format(a,b,lambdaSum(a,b)))


''' lambda 进阶 '''
def lambdaProduct(n):
    return lambda a : a * n

mydoubler = lambdaProduct(2)

print("lambdaProduct(3) : {}".format(lambdaProduct(3)))
print("lambdaProduct(3)(2) : {}".format(lambdaProduct(3)(2)))
print("mydoubler(11) : {}".format(mydoubler(11)))