与tkinter绑定时如何传递另一个参数？

Question

I just forayed into tkinter for the first time and am running into some issues. I want to display several lists to users, and store their selections for each list in a dictionary (used to filter several columns of a dataframe later). Suppose, for instance, there are two lists: 1) One labeled "Brand", containing 'Brand X' and 'Brand Y' as options, 2) another "Customer Type", containing "New," "Existing," "All."

In sum, when all is said and done, if a user picks "Brand X", "New", and "All", then I'd get a dictionary back of {'Brand':['Brand X'],'Customer Type':['New','All']}. Getting one list is easy... but looping through the lists is presenting problems.

I have the below code so far:

from tkinter import *
from tkinter import ttk


class checkList(Frame):
    def __init__(self, options, parent=None):
        Frame.__init__(self, parent)
        self.makeHeader()
        self.options = options
        self.pack(expand=YES, fill=BOTH, side=LEFT)
        self.makeWidgets(self.options)
        self.selections = []

    def makeHeader(self):
        header = ttk.Label(self,text='Please select options to limit on.')
        header.pack(side=TOP)
        self.header = header

    def makeWidgets(self, options):
        for key in self.options.keys():
            lbl = ttk.Label(self, text=key)
            lbl.pack(after=self.header)
            listbox = Listbox(self, selectmode=MULTIPLE, exportselection=0)
            listbox.pack(side=LEFT)
            for item in self.options[key]:
                listbox.insert(END, item)
            listbox.bind('<<ListboxSelect>>', self.onselect)
            self.listbox = listbox

    def onselect(self, event):
        selections = self.listbox.curselection()
        selections = [int(x) for x in selections]
        self.selections = [self.options[x] for x in selections]


if __name__ == '__main__':
    options = {'Brand':['Brand','Brand Y'], 'Customer Type': ['All Buyers','New Buyers','Existing Buyers']}
    checkList(options).mainloop()

Needless to say, the [self.options[x] for x in selections] works great with just one list, but since I have a dictionary, I really need [self.options[key][x] for x in selections]. However, I can't figure out how to pass the key at any given point in the loop. Is there a way to achieve what I'm trying to do?

Answer 1

The "magic" you're looking for to pass the key is simple because the tkinter objects are extensible. Here's your code working, I believe, the way you want:

from tkinter import *
from tkinter import ttk


class checkList(Frame):
    def __init__(self, options, parent=None):
        Frame.__init__(self, parent)
        self.makeHeader()
        self.options = options
        self.pack(expand=YES, fill=BOTH, side=LEFT)
        self.listboxes = [] # New
        self.makeWidgets(self.options)
        self.selections = {} # Changed

    def makeHeader(self):
        header = ttk.Label(self,text='Please select options to limit on.')
        header.pack(side=TOP)
        self.header = header

    def makeWidgets(self, options):
        for key in self.options.keys():
            lbl = ttk.Label(self, text=key)
            lbl.pack(after=self.header)
            listbox = Listbox(self, selectmode=MULTIPLE, exportselection=0)
            listbox.key = key # here's the magic you were asking about...
            listbox.pack(side=LEFT)
            self.listboxes.append(listbox) # New
            for item in self.options[key]:
                listbox.insert(END, item)
            listbox.bind('<<ListboxSelect>>', self.onselect)
            self.listbox = listbox

    def onselect(self, event):
        for lb in self.listboxes:
            selections = lb.curselection()
            selections = [int(x) for x in selections]
            self.selections[lb.key] = [self.options[lb.key][x] for x in selections]
        print(self.selections)


if __name__ == '__main__': #   \/
    options = {'Brand':['Brand X','Brand Y'], 'Customer Type': ['All Buyers','New Buyers','Existing Buyers']}
    checkList(options).mainloop()

Answer 2

With the code you posted, you only have access to the last ListBox created by makeWidgets in onselect .

With minimal changes:

from tkinter import *
from tkinter import ttk

class checkList(Frame):
    def __init__(self, options, parent=None):
        Frame.__init__(self, parent)
        self.listboxes = []
        self.selections = {}
        self.makeHeader()
        self.options = options
        self.pack(expand=YES, fill=BOTH, side=LEFT)
        self.makeWidgets(self.options)

    def makeHeader(self):
        header = ttk.Label(self,text='Please select options to limit on.')
        header.pack(side=TOP)
        self.header = header

    def makeWidgets(self, options):
        for key in self.options.keys():
            lbl = ttk.Label(self, text=key)
            lbl.pack(after=self.header)
            listbox = Listbox(self, selectmode=MULTIPLE, exportselection=0)
            listbox.pack(side=LEFT)
            for item in self.options[key]:
                listbox.insert(END, item)
            listbox.bind('<<ListboxSelect>>', self.onselect)
            self.listboxes.append(listbox)

    def onselect(self, event):
        for (option, options), listbox in zip(self.options.items(), self.listboxes):
            self.selections[option] = [options[x] for x in map(int, listbox.curselection())]
        print(self.selections)

if __name__ == '__main__':
    options = {'Brand':['Brand','Brand Y'], 'Customer Type': ['All Buyers','New Buyers','Existing Buyers']}
    checkList(options).mainloop()

This recreates selections every time either ListBox selection is modified. Alternatively, you could use event to determine which ListBox selection was modified and update the corresponding part of selections . This would require initializing selections , though.