Python | Column Mean in tuple list

Sometimes, while working with records, we can have a problem in which we need to average all the columns of a container of lists which are tuples. This kind of application is common in web development domain. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using sum() + list comprehension + zip()
This task can be performed using combination of above functions. In this, we cumulate the like index elements, i.e columns using zip(), and then iterate through them using list comprehension and perform summation using sum(). We divide the each result with No of rows for average computation.

Python3

# Python3 code to demonstrate working of
# Column Mean in tuple list
# using list comprehension + sum() + zip()

# initialize list
test_list = [(1, 2, 3), (6, 7, 6), (1, 6, 8)]

# printing original list
print("The original list : " + str(test_list))

# Column Mean in tuple list
# using list comprehension + sum() + zip()
res = [sum(ele) / len(test_list) for ele in zip(*test_list)]

# printing result
print("The Cumulative column mean is : " + str(res))

Output

The original list : [(1, 2, 3), (6, 7, 6), (1, 6, 8)]
The Cumulative column mean is : [2.6666666666666665, 5.0, 5.666666666666667]

Method #2 : Using zip() + map() + sum()
This method is similar to the above method. In this, the task performed by list comprehension is performed by map(), which extends the summation of columns to zipped elements. We divide the each result with No of rows for average computation.

Python3

# Python3 code to demonstrate working of
# Column Mean in tuple list
# using zip() + map() + sum()

def avg(list):
    return sum(list)/len(list)

# initialize list
test_list = [(1, 2, 3), (6, 7, 6), (1, 6, 8)]

# printing original list
print("The original list : " + str(test_list))

# Column Mean in tuple list
# using zip() + map() + sum()
res = list(map(avg, zip(*test_list)))

# printing result
print("The Cumulative column mean is : " + str(res))

Output

The original list : [(1, 2, 3), (6, 7, 6), (1, 6, 8)]
The Cumulative column mean is : [2.6666666666666665, 5.0, 5.666666666666667]