Python：如何在 Tkinter 上存储用户输入的文本？

Question

This is what i tried so far to get the user's input:

master = Tk()
master.title('Title')

v = StringVar()

L1 = Label(master, text = 'Name')
L1.pack(side = LEFT)

E1 = Entry(master, textvariable = v, bd = 5)
E1.pack(side = RIGHT)

def userinput():
    a = raw_input(v.get())
    print a


b = Button(master, text = 'Submit', command = userinput)
b.pack(side = BOTTOM)


master.mainloop()

The real question is, how can i store the v.get() raw_input into a variable outside the function? Thx!

Answer 1

You can make a global variable to hold the input:

inp = None

and then have your function update that variable:

def userinput():
    global inp
    a = raw_input(v.get())
    print a
    inp = a

So, your code will look like this:

master = Tk()
master.title('Title')

v = StringVar()

# Variable to hold the input
inp = None

L1 = Label(master, text = 'Name')
L1.pack(side = LEFT)

E1 = Entry(master, textvariable = v, bd = 5)
E1.pack(side = RIGHT)

def userinput():
    # Declare 'inp' to be global
    global inp
    a = raw_input(v.get())
    print a
    # Update the variable
    inp = a


b = Button(master, text = 'Submit', command = userinput)
b.pack(side = BOTTOM)


master.mainloop()

In the above code, inp will always be a fresh copy of the input which you can use elsewhere in the code.

However, it might be worthwhile to look into making your code a class. That way, you can have a class attribute named self.inp and you won't have to do global inp .

Answer 2

As others say - use globe

Example using class

from Tkinter import *

class MainWindow():

    def __init__(self, master):
        self.master = master

        self.master.title('Title')

        self.v = StringVar()

        self.L1 = Label(self.master, text = 'Name')
        self.L1.pack(side = LEFT)

        self.E1 = Entry(self.master, textvariable = self.v, bd = 5)
        self.E1.pack(side = RIGHT)

        self.B1 = Button(self.master, text = 'Submit', command = self.userinput)
        self.B1.pack(side = BOTTOM)

        self.B2 = Button(self.master, text = 'Print', command = self.print_external_variable)
        self.B2.pack(side = TOP)

    #------------------

    def userinput(self):
        global external_variable

        external_variable = raw_input(self.v.get())
        #external_variable = self.v.get()

        print "inside - userinput:", external_variable

    #------------------

    def print_external_variable(self):
        # you don't need global if you don't change external_variable

        print "inside - print:", external_variable

#----------------------------------------------------------------------

external_variable = '- none -'

print "before run:", external_variable

master = Tk()
MainWindow(master)
master.mainloop()

print "after run:", external_variable

Answer 3

First of all, why using raw_input to take input when you can do the same with the entry widget?

There are few disadvantages of following the above practice:

• raw_input will cause the whole python interpreter to pause, but entry widget wont do that.
• raw_input can't be customized or it's bit hard to customize, but we can easily do that for entry widget.
• If you press the button again without entering data in raw_input , it will raise an error, but in entry widget it wont.

and for your problem's solution, there are 3 methods.

method 1:

• is to update the textvariable value, then you can access it using v.get() . ( Best )

def userinput():
    a = raw_input(v.get())
    v.set(a)
# This would also cause an update in entry widget.

method 2:

• is to use global keyword inside the function and store the raw_input 's data to the global variable.

def userinput():
    global data
    data = raw_input(v.get())

method 3:

• is to update the text value of the button or entry box, then you can access it using b.cget("text") . ( changing text value is practically not useful, but still a method. )

def userinput():
    a = raw_input(v.get())
    b.config(text=a)

I would suggest you to use method 1.

Answer 4

Just make it return the User Input

def userinput():
    a = raw_input(v.get())
    return a

Then when you call it,you can do that by:

myvar=userinput()

Now, myvar contains the value of user input.