Python: Why “return” won´t print out all list elements in a simple for loop and “print” will do it?

Question

Im trying to print out all elements in a list, in Python, after I´ve appended one list to another. The problem is that it only prints out every element when I use PRINT inst

Answer 1

When you use a return statement, the function ends. You are returning just the first value, the loop does not continue nor can you return elements one after another this way.

print just writes that value to your terminal and does not end the function. The loop continues.

Build a list, then return that:

def union(a,b):
    a.append(b)
    result = []
    for item in a:
        result.append(a)
    return result

or just return a concatenation:

def union(a, b):
    return a + b