# Python | Average of two lists

• Difficulty Level : Basic
• Last Updated : 19 Feb, 2020

The problem of finding a average values in a list is quite common. But sometimes this problem can be extended in two lists and hence becomes a modified problem. This article discusses shorthands by which this task can be performed easily. Let’s discuss certain ways in which this problem can be solved.

Method #1 : Using `sum() + len() + “+” operato`r
The average value can be determined by the conventional sum() and len function of python and the extension of one to two lists can be dealt using the “+” operator.

 `# Python3 code to demonstrate``# Average of two lists``# using sum() + len() + "+" operator`` ` `# initializing lists``test_list1 ``=` `[``1``, ``3``, ``4``, ``5``, ``2``, ``6``]``test_list2 ``=` `[``3``, ``4``, ``8``, ``3``, ``10``, ``1``]`` ` `# printing the original lists``print` `(``"The original list 1 is : "` `+` `str``(test_list1))``print` `(``"The original list 2 is : "` `+` `str``(test_list2))`` ` `# Average of two lists``# using sum() + len() + "+" operator``res ``=` `sum``(test_list1 ``+` `test_list2) ``/` `len``(test_list1 ``+` `test_list2)`` ` `# printing result``print` `(``"The Average of both lists is : "` `+` `str``(res))`
Output :
```The original list 1 is : [1, 3, 4, 5, 2, 6]
The original list 2 is : [3, 4, 8, 3, 10, 1]
The Average of both lists is : 4.166666666666667
```

Method #2 : Using `sum() + len() + chain()`
Another method to perform this particular task is by using the chain function which performs the task similar to the “+” operator but using an iterator, hence faster.

 `# Python3 code to demonstrate``# Average of two lists``# using sum() + len() + "+" operator``from` `itertools ``import` `chain`` ` `# initializing lists``test_list1 ``=` `[``1``, ``3``, ``4``, ``5``, ``2``, ``6``]``test_list2 ``=` `[``3``, ``4``, ``8``, ``3``, ``10``, ``1``]`` ` `# printing the original lists``print` `(``"The original list 1 is : "` `+` `str``(test_list1))``print` `(``"The original list 2 is : "` `+` `str``(test_list2))`` ` `# Average of two lists``# using sum() + len() + "+" operator``res ``=` `sum``(chain(test_list1, test_list2)) ``/` `len``(``list``(chain(test_list1, test_list2)))`` ` `# printing result``print` `(``"The Average of both lists is : "` `+` `str``(res))`
Output :
```The original list 1 is : [1, 3, 4, 5, 2, 6]
The original list 2 is : [3, 4, 8, 3, 10, 1]
The Average of both lists is : 4.166666666666667
```

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