使用 python function 的一部分的结果并存储在 function 外部的变量中

Question

In my program I am calling a function that imports.csv data into a treeview using tkinter and csv module. The Function is only called when the Import button is used. The import button is linked to function select_input_file . The function works as expected and the csv data is imported into my treeview without any issues. From here I would like to store some of the function results into variables outside the function. For instance the input_file_path which will only contain a value once the function is called and a file is imported. Also data imported into Ro Number, Rego Number columns. I have attempted to use return() but it stops the function from running any further. I have also read up on yield but through documentation im not sure if this is my best option. I thought a solution could be to use return() and then for in rdr: after each return so the select_input_file function continued but Im sure theres a better way?? Ive cut the code down to what I thought was necessary.

import tkinter as tk
from tkinter import *
import tkinter.ttk as tkrttk
import csv


root = tk.Tk()

treetime = tkrttk.Treeview(root)
treetime['columns'] = ("Column2", "Column3", "Column4", "Column5",
                       "Column6", "Column7", "Column8", "Column9", "Column10", "Column11")

def select_input_file():
            input_file_path = filedialog.askopenfilename(
                filetypes=(("CSV files", "*.csv"),))
            with open(input_file_path) as csv_file:
              rdr = csv.DictReader(csv_file)
              for row in rdr:
                 RoNumber = row['Ro Number']
                 DateIn = row['Date In']
                 TimeIn = row['Time In']
                 TimeOut = row['Time Out']
                 RegoNumber = row['Rego Number']
                 CustomerName = row['Customer Name']
                 VehicleMake = row['Vehicle Make']
                 VehicleModel = row['Vehicle Model']
                 JobDescription = row['Job Description']
                 CurrentStatus = row['Current Status']

                 treetime.insert("", 0, values=(RoNumber, DateIn, TimeIn, TimeOut, RegoNumber,
                                           CustomerName, VehicleMake, VehicleModel, JobDescription, CurrentStatus))

menubar=Menu(root)
filemenu=Menu(menubar, tearoff=0)
filemenu.add_command(label="Import", command=select_input_file)
               
    root.mainloop()      

Answer 1

For your specific question: you can't return and continue executing within a function. You could get that effect with yield , but I think it would be abusing the semantics and could just give you future headaches. You can return more than one thing:

def foo():
    return "Spam", 42

def bar():
    name, answer = foo()

This would let you return (eg) the selected filename and data from the file to the calling function.

A more general comment: functions should generally do one thing. This makes them easier to test (the purpose is clear) and easier to modify (fewer if any side effects). Right now your function is getting user input (filename), loading and parsing the file contents, and updating the control. You may want to have separate functions that do these different things, and are just brought together by a short function that is invoked when 'Import' is clicked. Your original question might be easier to address this way, too.