**Mean, also known as average is the sum of all the terms divided by a number of terms.** In other words, it is the average of all the numbers.

** **

Mean can be calculated using a loop, using sum() and len() functions, or by importing statistics module.

**sum() and len() are inbuilt functions in python to calculate the sum and number of elements of a numeric data set respectively.**

Consider a list** num_list = [5, 3, 2, 8, 9, 1].** The value returned by **sum()** function is stored in a variable **add **and the value returned by function **len()** is stored in variable **num_terms.**

The variable **add** is divided by **num_terms** to get the mean value.

```
num_list = [5, 3, 2, 8, 9, 1]
add = sum(num_list)
num_terms = len(num_list)
mean = add / num_terms
print("The mean of all the terms is: ", mean )
```

Output

`The mean of all the terms is: 4.666666666666667`

Python supports a built-in module known as statistics, to calculate statistics of numeric data. **statistics.mean()** can be used to calculate the mean of numbers in a data set. The statistics module can be used with data set like lists, tuple, or sets.

```
import statistics
num_set = {5, 3, 2, 8, 9, 1}
avg = statistics.mean(num_set)
print("The mean of all the terms is: ", avg)
```

Output

`The mean of all the terms is: 4.666666666666667`

Let us consider **num_list = [5, 3, 2, 8, 9, 1]. **A variable **num_terms** is initialized to** '0'**, to count the number of terms. A **for loop** is used to iterate over the list **num_list.** After encountering every element the value is added to the variable **add** and **num_terms** is incremented by 1. The variable **add** is divided by **num_terms** to get the mean value.

```
num_list = [5, 3, 2, 8, 9, 1]
add = 0
num_terms = 0
for i in num_list:
add += i
num_terms += 1
mean = add / num_terms
print("The mean of all the terms is: ", mean )
```

Output

`The mean of all the terms is: 4.666666666666667`

Python supports a built-in module known as statistics, to calculate statistics of numeric data. **statistics.mean()** can be used to calculate the mean of numbers in a data set. The statistics module can be used with data set like lists, tuple, or sets.

```
import statistics
num = {5,3,2,8,9,1}
avg = statistics.mean(num)
print("The mean of all the terms is: ",avg)
```

Output

`The mean of all the terms is: 4.666666666666667`

If anything other than numeric values is present in the sequence as a **TypeError** Exception is raised.

For example,

```
num_list = [5, 3, 2, 8, 9, 1, "Hello"]
add = sum(num_list)
num_terms = len(num_list)
mean = add / num_terms
print("The mean of all the terms is: ", mean )
```

Output

```
add = sum(num)
TypeError: unsupported operand type(s) for +: 'int' and 'str'
```