试图计算浮动列表的平均值？

Question

I don't know if I'm going about getting the float values the right way but this is what I have so far.

grades_file = open('grades.txt', 'r')

# Print Header & spacer
print('Name' + '\t\tGrade')
print('---------------------')

# Read lines & store grades
for file_lines in grades_file:
    lines = file_lines.rstrip('\n')

    num_list = re.findall(r"[-+]?\d*\.\d+|\d+", lines)
    grades = [float(num) for num in num_list]
    average = statistics.mean(grades)

    print(lines)
    print(average)

Now I'm trying to get it to print what's in the file and print the average of the numbers separately but this is what I'm getting.

Output:

    Name        Grade
---------------------
   Mickey,Mouse 90.0
   90.0
   Jane,Doe     50.0
   50.0
   Minnie,Mouse 95.0
   95.0
   Donald,Duck  80.0
   80.0
   Daffy,Duck   70.0
   70.0

What am I doing wrong here?

Edit: The contents of num_list :

['90.0']
['50.0']
['95.0']
['80.0']

When I try to just print num_list it shows up similar to printing average.

Contents of the input file:

Mickey,Mouse 90.0
Jane,Doe     50.0
Minnie,Mouse 95.0
Donald,Duck  80.0
Daffy,Duck   70.0

Answer 1

I managed to figure it out. I don't know why but I had to put the grade average in a separate function

def grade_avg():
    grades_file = open('grades.txt', 'r')
    file_contents = grades_file.read()

    num_list = re.findall(r"[-+]?\d*\.\d+|\d+", file_contents)
    grades = [float(num) for num in num_list]
    average = mean(grades)

    print('Average Grade:', average)

It seems like a long workaround but it works.

Answer 2

You are using the regex function inside the for loop of each line of the file. So you are calculating the average of a single number.

You need to calculate the average first, and then print each line contents:

import re
import statistics

with open('grades.txt', 'r') as grades_file:
    # Print Header & spacer
    print('Name' + '\t\tGrade')
    print('---------------------')

     #get all grades from file
    
    
    # Read lines & store grades
     #reset file position
    for file_lines in grades_file:
        lines = file_lines.rstrip('\n')
        print(lines)
        print(average)