Question: I am new to Python. How can I know if a function is being used or not; if it is not equal to zero then the program will print; otherwise, do not print any zero.

```
b1 = (int(a1[0]) + int(a2[0])) // 10
b2 = (int(a1[1]) + int(a2[1])) // 10
b3 = (int(a1[2]) + int(a2[2])) // 10

if (b1,b2,b3) !=0:
     print (b1, b2, b3)

```

Answer: 
Welcome to Stack Overflow!

In Python, `(b1,b2,b3)` represents a `tuple` object. And it is obviously not equal to the int object zero, so your if condition is always satisfied.

You can change your code to this if you want to print when any of the three is not zero:

```
if b1 != 0 or b2 != 0 or b3 != 0:
    print(b1,b2,b3)

```
As it's array instead of checking values like that you can even use loop 

```
for i in range(3):
    if int(a1[i]) + int(a2[i]) != 0:
        print(int(a1[i]) + int(a2[i]))

```

This will print only the answers which are not equal to zero.