Python: How do you call an attribute from one function into another?

Question

This is the code:

from tkinter import *
import os

class App:

    charprefix = "character_"
    charsuffix = ".iacharacter"
    chardir = "data/characters/"
    charbioprefix = "character_biography_"

    def __init__(self, master):
        self.master = master
        frame = Frame(master)
        frame.pack()

        # character box
        Label(frame, text = "Characters Editor").grid(row = 0, column = 0, rowspan = 1, columnspan = 2)
        self.charbox = Listbox(frame)
        for chars in []:
            self.charbox.insert(END, chars)
        self.charbox.grid(row = 1, column = 0, rowspan = 5)
        charadd = Button(frame, text = "   Add   ", command = self.addchar).grid(row = 1, column = 1)
        charremove = Button(frame, text = "Remove", command = self.removechar).grid(row = 2, column = 1)
        charedit = Button(frame, text = "    Edit    ", command = self.editchar).grid(row = 3, column = 1)

        for index in self.charbox.curselection():
            charfilelocale = self.charbox.get(int(index))
            charfile = open(app.chardir + app.charprefix + charfilelocale, 'r+')
            charinfo = self.charfile.read().splitlines(0)

Now what I want to know is, if I'm going to call charinfo in another function, what should I call it? I'm using Python 3.3 and app.charinfo or self.charinfo don't work. If my code is incorrect, can you help please correct it too? Thanks in advance.

You cant call it, it is local variable of a function its scope is inside that function. if you want to use it in another class declare it as a class variable means instaed of charinfo type self.charinfo — duck, Aug 14 '13 at 06:26

score 0 · Accepted Answer · answered Aug 14 '13 at 06:26

Your current implementation declares it as a local variable, and hence in accessible outside. For that to work, the assignment needs to happen onto self.charinfo:

When you want to access charinfo from other places
- self.charinfo works from within the class definition, and
- app.charinfo works outside class / from the instance

for index in self.charbox.curselection():
    charfilelocale = self.charbox.get(int(index))
    charfile = open(app.chardir + app.charprefix + charfilelocale, 'r+')
    # notice the self.charinfo here
    self.charinfo = self.charfile.read().splitlines(0)

Its better to ensure the attribute self.charinfo is available outside the loop to avoid errors in case it loops 0 times

self.charinfo = None
for index in self.charbox.curselection():
    charfilelocale = self.charbox.get(int(index))
    charfile = open(app.chardir + app.charprefix + charfilelocale, 'r+')
    self.charinfo = self.charfile.read().splitlines(0)

@PithiratHorvichien I am afraid it maybe something specific to your application. I merely conveyed the usage. — Kalyan02, Aug 14 '13 at 07:02

Python: How do you call an attribute from one function into another?

1 Answers1