creating sum of odd indexes python
<p>I'm trying to create a function equal to the sum of every other digit in a list. For example, if the list is [0,1,2,3,4,5], the function should equal 5+3+1. How could I do this? My knowledge of Python does not extend much farther than while and for loops. Thanks. </p>

<p>Here is a simple one-liner:</p>

<pre><code>In [37]: L
Out[37]: [0, 1, 2, 3, 4, 5]

In [38]: sum(L[1::2])
Out[38]: 9
</code></pre>

<p>In the above code, <code>L[1::2]</code> says "get ever second element in <code>L</code>, starting at index 1"</p>

<p>Here is a way to do all the heavy lifting yourself:</p>

<pre><code>L = [0, 1, 2, 3, 4, 5]
total = 0
for i in range(len(L)):
    if i%2:  # if this is an odd index
        total += L[i]
</code></pre>

<p>Here's another way, using <code>enumerate</code>:</p>

<pre><code>L = [0, 1, 2, 3, 4, 5]
total = 0
for i,num in enumerate(L):
    if i%2:
        total += num
</code></pre>

python for-loop while-loop sum