return

Learn to return values with return.

Returning values with return

A function can compute and return a value; for this, use return:

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

result = add(3, 4)  # 7

When return runs, the function ends and the value goes to the caller. Without return, the function returns None.

Most functions return a value; this value can be passed to another function.

print writes a value to the screen but does not return it. return gives the value to the caller:

def show(x):
    print(x)   # writes to screen, returns None

def give(x):
    return x  # returns, does not print

These two are often confused. If you will use the result elsewhere, use return; to just see it, use print.

Define a function called add that takes two parameters a and b and returns a + b. Assign add(3, 4) to result. Then print print(result).

Show example solution

def add(a, b):
    return a + b
result = add(3, 4)
print(result)

Complete the return expression

def add(a, b):
    ____ a + b

Show answer

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

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