How To Use Python Program To Calculate The Average Of Numbers In A Given List

This example will tell you how to calculate a list of number’s average values in python.

1. Use Python To Calculate Average Number Of A Number List Example1.

# This function is used to calculate the average number of a list number.
def calculate_average_number_in_list(list):
    
    # If the list object is not none.
    if list:
        
        # Used to save summarize value of the number list value.
        sum = 0.0
       
        # Number type list element counter.
        number_type_element_count = 0
       
        # Loop in the list object.
        for value in list:
            
            # If the list element is a number.
            if is_number(value):
                
                # Number type list element counter plus 1.
                number_type_element_count = number_type_element_count + 1
                
                # Convert the value to a float number.
                float_number = float(value)
                
                # Add the number to the summarize value.
                sum = sum + float_number
                
                
        # Calculate the average number value of the number list.    
        average_number = sum / number_type_element_count 
        
        print('Average number of list : ')
        
        print(list)
        
        print('is')
        
        print(average_number)  
   
        
''' check whether the value can be converted to a float number value.
 If the value is a string and contains no digit value, then it can not be converted to a float number.'''      
def is_number(value):
    
    ret = True
    try:
        float_value = float(value)
        print('\'' + value + '\' is a number.')
    except:
        print('\'' + value + '\' is not a number.')
        ret = False
    finally:
        return ret    
        
            

if __name__ == '__main__':
    
    # Create a list with number and none number string.
    list = [1,2,3,4,5,"6",7,8.1,'abc','10']
    
    calculate_average_number_in_list(list)

Before is the above source code execution result.

'6' is a number.
'abc' is not a number.
'10' is a number.
Average number of list : 
[1, 2, 3, 4, 5, '6', 7, 8.1, 'abc', '10']
is
5.122222222222223

2. Calculate User Input Number List Average Value In Python.

from builtins import input
        
''' check whether the value can be converted to a float number value.
 If the value is a string and contains no digit value, then it can not be converted to a float number.'''      
def is_number(value):
    
    ret = True
    try:
        float_value = float(value)
        print('\'' + value + '\' is a number.')
    except:
        print('\'' + value + '\' is not a number.')
        ret = False
    finally:
        return ret    
        
        
        
def calculate_user_input_number_list():
    
    number_count = eval(input("How many numbers in the list?"))
    
    sum = 0
    
    for i in range(number_count):
        
        x = eval(input("Enter a number : "))
        
        if is_number(x):
            
            sum = sum + float(x)
            
        else:
            
            print("Your input value\' " + x +"\' is not a number, program exit. ")
            
            return    
        
    average_value = sum / number_count
    
    
    # str(average_value) will avoid the TypeError: can only concatenate str (not "float") to str.
    print("\nThe average valur is: " + str(average_value))  
        
            

if __name__ == '__main__':
    
    calculate_user_input_number_list()

Below is the above source code execution result.

How many numbers in the list?3
Enter a number : 89
Enter a number : 63
Enter a number : 98

The average valur is: 83.33333333333333

If your input is not a number type, then it will show the below output in the console.

How many numbers in the list?3
Enter a number: 1
Enter a number: "6"
'6' is a number.
Enter a number: "abc"
'abc' is not a number.
Your input value 'abc' is not a number, program exit.