I want to make a program that take integer input from user and sum those. There is no fixed amount of parameter

Question

I want to make a program that take integer input from user and sum those. There is no fixed amount of parameter. So I write this code. But there is an error. Hope I will get a solution.

Code:

def sum(*args):
    tmp = 0
    for number in args:
        tmp = tmp + number
    return tmp

temp = [int(i) for i in input().split()]
sum(temp)
print(temp)

Error:

10 20 30
Traceback (most recent call last):
  File "D:/PyCharm/test2.py", line 8, in <module>
    sum(temp)
  File "D:/PyCharm/test2.py", line 4, in sum
    tmp = tmp + number
TypeError: unsupported operand type(s) for +: 'int' and 'list'

Process finished with exit code 1 

Answer 1

You need to unwrap your list before passing it in:

sum(*temp)

That way, args will be the list [10, 20, 30] . Instead if you just call sum(temp) then args will be a list of the arguments so it will just end up being a single element list of a list [[10, 20, 30]] which is not what you want

Answer 2

Your sum() function puts all arguments passed to it in a tuple, because you used *args . You called the sum() function with one argument, which is a list. So args is a tuple with one element, a list:

>>> def demo(*args): return args
...
>>> demo([42, 81])
([42, 81],)

You then loop over the tuple, and tried to sum the list object.

Either remove the * from the args parameter (and just accept a single argument), or pass the values of your list to sum() by using the * in the call too:

def sum(args):
    # ... all the same code

# ...
result = sum(temp)

or

result = sum(*temp)

You are also ignoring the return value of the sum() function and are printing the inputs. If you wanted to print the result, then pass that result to print() . In the above examples I added a result variable, print that variable.

Answer 3

There are two errors:

after calling sum(temp) , you should assign result to a variable and print it.

sum should take list, not *list.

Your code should look like this:

def sum(args):
    tmp = 0
    for number in args:
        tmp = tmp + number
    return tmp

temp = [int(i) for i in input().split()]
result = sum(temp)
print(result)

Prints:

$ python3 suminputs.py
3 4 5
12 
$