How to correct the output from an entry box

When using the feeder button, the script for F runs through entirely through to the print before the 'master' box appears, then does not react to the inputs from the 'master' box. This results in the output being 0.0 kW because the input is a long decimals followed by an L, when what I, the user inputs is 8777

I have been roaming the internet for about a day now with no luck finding anything. I am very new to TK but have been trying to learn it.

def F():
    master = tk.Tk()
    tk.Label(master, text = 'Feeder Number: ').grid(row=0)
    entry1 = tk.Entry(master)
    entry1.grid(row=0, column=1)
    button2 = tk.Button(master,
                        text=' Confirm',
                        command=entry1.get())
    button2.pack()
    button2.grid(row=0, column=2)
    fn = entry1.pack()
    print fn
    feed = filtered['Feeder']==fn
    feedfn = filtered[feed]
    Cap = feedfn['AC Name Plate Capacity <= 10kw']
    Cap = Cap.astype(float)
    AcPv = Cap.sum()
    print 'The total PV on this feeder is:', AcPv, 'kW'

root = tk.Tk()
frame = tk.Frame(root)
frame.pack()

button = tk.Button(frame,
                   text='Exit',
                   fg='red',
                   command=quit)
button.pack()
button.grid(row=1, column=1)

Fee = tk.Button(frame,
                text='Feeder',
                command=F)
Fee.pack()
Fee.grid(row=0, column=1)

root.mainloop()

Expected 27.702 Output 0.0 Given that I will not be posting the csv, entry1/fn should be 8777

currently 'none'

UPDATE I am now receiving an output of PY_VAR when printing fn, I understand that the code is running all the way through before taking an input. Any recommendations for how to take the input before the filters are run?

def F():
    master = tk.Tk()
    tk.Label(master, text = 'Feeder Number: ').grid(row=0)
    entry1 = tk.Entry(master)
    entry1.grid(row=0, column=1)
    button2 = tk.Button(master,
                        text=' Confirm',
                        command=entry1.get())
    button2.grid(row=0, column=2)
    fn = tk.IntVar()
    print fn
    feed = filtered['Feeder']==fn
    feedfn = filtered[feed]
    Cap = feedfn['AC Name Plate Capacity <= 10kw']
    Cap = Cap.astype(float)
    AcPv = Cap.sum()
    print 'The total PV on this feeder is:', AcPv, 'kW'

For those interested in the final code (Which worked for me):

def F():
    master = tk.Tk()
    tk.Label(master, text = 'Feeder Number: ').grid(row=0)

    entry = tk.Entry(master)
    entry.grid(row=0, column=1)

    def pint():
        data = entry.get()
        master.destroy()
        feed = filtered['Feeder']==data
        feedfn = filtered[feed]
        Cap = feedfn['AC Name Plate Capacity <= 10kw']
        Cap = Cap.astype(float)
        AcPv = Cap.sum()

        fdf = tk.Tk()
        tk.Label(fdf, text = AcPv).grid(row=0)

        button4 = tk.Button(fdf,
                            text = ' Exit',
                            fg='red',
                            command=fdf.destroy)
        button4.grid(row=1)

    button2 = tk.Button(master,
                        text=' Confirm',
                        command = pint)
    button2.grid(row=0, column=2)

    button3 = tk.Button(master,
                        text = ' Exit',
                        fg='red',
                        command=master.destroy)
    button3.grid(row=0, column=3)

    master.mainloop()

Solution

There a few mistake in your code that lead to the different output you have received.

First, why is your code executing without showing the master box :

Your tkinter need a mainloop() call if you want a persistent window.

master.mainloop()

You did that right with your root, but your master lacks that mainloop. This line is what basically keeping your GUI alive and looping over it for changes until it is destroyed one way or another. You need to add this line after creating your widgets in order to be able to interact with the window. Anything written after this line (but still indented in the definition) will be executed when your window is closed, either manually or with the command :

master.destroy()

Next, although this will yield a working window, you can still interact with your root window while the master window is up, which can lead to problems if you are expecting variable from master. I suggest you read about the Toplevel widget which is made specifically for cases like yours. (http://effbot.org/tkinterbook/toplevel.htm) Alternatively, you could also use tkinter's tkSimpleDialog.askinteger or askfloat functions which seems perfect for your application.

Finally, the entry allows you to write text but how to access the text? you can use Entry1.get() to extract the content of the entry, or as you have started to to in your update, you can assign a tkinter variable to the entry. This variable will be updated as you change write strings or numbers in the entry. To bind the variable to your entry, you must state it in the entry's creation :

fn = tk.StringVar(value = '000')
entry1 = tk.Entry(master, textvariable = fn)

*Note, this will require your fn variable to be initialized before the entry. Also, you can initialize a value for that variable upon creation

the tkinter variable is an object which is why when you print it, you get PY_VAR. (the type of object) To access the value, you need to use the get() method :

print(fn.get())