The for loop revisited¶

Recall that the for loop processes each item in a list. Each item in turn is (re-)assigned to the loop variable, and the body of the loop is executed. We saw this example in an earlier chapter.

• We have also seen iteration paired with the update idea to form the accumulator pattern.
• For example, to compute the sum of the first n integers, we could create a for loop using the range to produce the numbers 1 through n.
• Using the accumulator pattern, we can start with a running total variable initialized to 0 and on each iteration, add the current value of the loop variable.