Python中的简单求和程序

Question

I just wrote this very simple Python script which finds the sum of two integers. I'm just trying to understand how the return values are assigned to variables:

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

first_number, second_number, result = add(3,4)

print 'first_number is ', first_number
print 'second number is ', second_number
print 'result is ', result

When I try to run this script, I get the following:

Traceback (most recent call last):
  File "test.py", line 7, in <module>
    first_number, second_number, result = add(3,4)
TypeError: 'int' object is not iterable

Why is that? And, how can I solve this issue?

Answer 1

Your problem is that the return a statement stops the routine and returns only one value, but the main program expects three values. Your other return statements are never executed.

Instead, use just one return statement:

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