如何将数学方程式从函数写入文件？

Question

I'm trying to stats from a file and calculate the mean,median,min and max. This much I've been able to do.

Where I'm struggling is I need to then give the user an option to save the computed stats to a new file. It's giving me an error that's saying 'str' object has no attribute 'write'

Does anyone know how I could write my "computed_stats" function to a file? I'd really appreciate any help!

Here is a screen shot of the bulk of my code. I didn't have enough screen space to include the table that prompts the user to enter selections or the function that loads data. They didn't seem important for this issue.

def table():
    print("Choose an option:")
    print("1. Load data")
    print("2. Display computed statistics")
    print("3. Save computed statistics")
    print("4. Exit")

def load_data(filename):
    with open(filename) as f:
        for lines in f:
            numbers = lines.split()
            return(numbers)

def compute_stats(data_list):

    minimum = (min(data_list))
    maximum = (max(data_list))
    mean = (sum(data_list) / (len(data_list)))
    data = sorted(data_list)
    if (len(data) % 2) == 1:
        median = data[len(data) // 2]      
    else:
        median = (data[len(data) // 2] + data[len(data) // 2 - 1]) / 2
    return minimum, maximum, mean, median

def print_stats(data_list):
    minumum, maximum, mean, median = compute_stats(data_list)
    print(minimum)
    print(maximum)
    print(mean)
    print(median)


def save_stats(new_file):
    global comp_data    
    with open(new_file, 'w') as f:        
        f.close()



def main():


    selection = 0
    while selection != "4":
        table()
        selection = input("Choose a selection: ")
        print()

        if selection == "1":
            data_list = input("Enter the name of your file: ")
            data_list = load_data(data_list)
            data_list = [int(x) for x in data_list]
            print("Data read sucessfully \n")


        elif selection == "2":          
            print_stats(data_list)


        elif selection == "3":
            new_file = input("Enter File Name")
            save_stats(new_file)


main()

Answer 1

One classical problem that you have here is that you have mixed up presentation of the results with the computation. In your code, the computed_stats function does both the printing and the computing. By the way, it is badly named, something like print_statistics might be better. Often, when your function names don't naturally start with a verb, their responsibilities are badly defined.

For a very first change I would do something like this:

def compute_statistics(data_list):
    # Do whatever computations you need but don't print anything
    minimum = #Insert computation for minimum here
    maximum = #Insert computation for maximum here
    mean = #Insert computation for mean here
    median = #Insert computation for median here
    return minimum, maximum, mean, median # whatever statistics you are computing

def print_statistics(data_list):
    minimum, maximum, mean, median=compute_statistics(data_list)
    # Put your printing logic here using the results from above

def save_statistics(file_name, data_list):
    minimum, maximum, mean, median=compute_statistics(data_list)
    with open(file_name,'w') as outfile:
        file.write(f"min = {minimum}\n")
        # Put all your saving logic here

If you want the printed version to look exactly like the saved version, you might also add a function for generating that string, that you can call upon from print_statistics and save_statistics .

Later on, you might wish to think about how to better manage the state of your application so that you don't have to recompute statistics every time. But that is a story for another time.