1. 关键字参数
2. 默认参数 
3. 不定长参数

def print_info(name, age, sex="Male"):
    print("Name={}, Age={}, Sex={}".format(name, age, sex))

print_info('Ruby', 30)  # 必须字参数
print_info(name='Ruby', age=30)  # 关键字参数
print_info('Kevin', 36, 'Female')  # 默认参数
# print_info('Kevin', 36, 'Female','IT')


def add(*args):
    sum = 0
    for num in args:
        sum += num
    print(sum)
    return sum

print(id(add))
add(2, 3, 1, 4) #不定长参数