To find the average value (also known as the mean) in a list in Python, you can calculate the sum of the values and divide it by the total number of values. Here's an example:
my_list = [4, 2, 9, 1, 7]
average = sum(my_list) / len(my_list)
# Output: 4.6
In this example, the sum() function is used to calculate the sum of the values in the list my_list. The length of the list, obtained using the len() function, gives the total number of values. The sum is then divided by the total number of values to calculate the average, which is stored in the variable average and printed.
Note that the result is a floating-point number, as the division may produce a fractional value. If you prefer to have the average as an integer or a specific decimal precision, you can format the result accordingly using formatting functions or string formatting options.
It's important to handle the case where the list is empty to avoid a ZeroDivisionError. You can add a check for an empty list before calculating the average to handle this case appropriately.