Using for loops with lists

As you are aware by now, a for loop iterates over iterable things—and lists are iterable!

An example of a for loop iterating over a list:

In this example, the first time the body of the loop is evaluated, x has a value equal to the first element in the list (i.e., element at index 0), which is 5.

• First iteration: x has a value of 5, the body of the loop is evaluated with this value of x

• Second iteration: x has a value of the next member in the sequence, 2, and the body of the loop is evaluated with this value of x

• Third iteration: x has a value of the next member in the sequence, 3, and the body of the loop is evaluated with this value of x

• Fourth iteration: x has a value of the next member in the sequence, 1, and the body of the loop is evaluated with this value of x

• Since there are no more members to iterate over in the sequence of members, the for loop is done being evaluated

This loop would print:

5
2
3
1

Similarly, if we want to find the sum of all elements inside a list, then we can use a for loop to achieve it as follows:

This for loop iterates over each element in the list and adds it to the variable sum_of_elements which holds the total sum of all the elements in the list. The output of the above code snippet is:

94