def total(numbers)sum_so_far these variables exist only within the function' body for number in numberssum_so_far +number the numbers name we specified on the def line is visible to python only within the function definition similarly any names that get created within the function body exist only within that function body and will not be visible outside nor will they clash with any other uses of those names outside the function body in our example code the name "numbersis defined in the def linethe "sum_so_farname is defined explicitly in the function body and the "numbername is defined by the for loop as its loop variable none of these interact with the python outside the function definition