I am using a function to call another function. When return the value, I am getting: 'NoneType' object is not subscriptable

I am using a function to call another function. When I run the code, I am getting:

‘NoneType’ object is not subscriptable

How can I get the return value and print them?

e.g ) I run the code , a = equation 2 , b = 10 , c = 2
This will enter test_2, but I cant print the results from function test_2.

a = input('enter eqution')
b = int(input('enter b'))
c = int(input('enter c'))

y_list = []
x_list = []


def test_1(x , y , z):
    if x == "euqation 1"
        test_2(y,z)

    elif x == "equation 2"
        test_3(y,z)

def test_2(angle , c):
    for i in range(0 , angle , 1):
        y = (i * 3)**c
        y_list.append(y)
        x_list.append(i)        
    return ( y_list , x_list , y )


def test_3(angle , c):
    for i in range(0 , angle , 1):
        y = (i * 5)**c
        y_list.append(y)
        x_list.append(i)        
    return ( y_list , x_list , y )



result  = test_1(a , b , c)
print(result[0])
print(result[1])
print(result[2])

>Solution :

Your test_1 function doesn’t return nothing, it should be:

def test_1(x , y , z):
    if x == "euqation 1"
        return test_2(y,z)

    elif x == "equation 2"
        return test_3(y,z)