Python sum() function with list parameter

python list int sum typeerror
Ro Mc picture Ro Mc · Sep 11, 2013 · Viewed 165.7k times · Source

I am required to use the sum() function in order to sum the values in a list. Please note that this is DISTINCT from using a for loop to add the numbers manually. I thought it would be something simple like the following, but I receive TypeError: 'int' object is not callable.

numbers = [1, 2, 3]
numsum = (sum(numbers))
print(numsum)

I looked at a few other solutions that involved setting the start parameter, defining a map, or including for syntax within sum(), but I haven't had any luck with these variations, and can't figure out what's going on. Could someone provide me with the simplest possible example of sum() that will sum a list, and provide an explanation for why it is done the way it is?

Answer

flornquake picture flornquake · Sep 11, 2013

Have you used the variable sum anywhere else? That would explain it.

>>> sum = 1
>>> numbers = [1, 2, 3]
>>> numsum = (sum(numbers))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'int' object is not callable

The name sum doesn't point to the function anymore now, it points to an integer.

Solution: Don't call your variable sum, call it total or something similar.

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