def outer_func(num):
    # 중첩 함수에서 외부 함수의 변수에 접근 가능
    def inner_func():
        print(num)
        return '안녕'
    
    return inner_func                 # 중첩 함수 이름을 리턴합니다.

closure_func = outer_func(10)    # <--- First-class function
closure_func()            # <--- Closure 호출 

del outer_func

closure_func()

def calc_square(digit):
    return digit * digit

def calc_power_3(digit):
    return digit * digit * digit

def calc_quad(digit):
    return digit * digit * digit * digit

print (calc_square(2))
print (calc_power_3(2))
print (calc_quad(2))

def calc_power(n):
    def power(digit):
        return digit ** n
    return power

power2 = calc_power(2)
power3 = calc_power(3)
power4 = calc_power(4)

print (power2(2))
print (power3(2))
print (power4(2))

list_data = list()
for num in range(1, 6):
    list_data.append(calc_power(num))

for func in list_data:
    print(func(2))