tkinter中的用户输入是否存储为“条目”而不是“ int”？

Question

I'm using tkinter to obtain a list of x and y coordinates from the user. An initial pop up obtains the number of coordinates and then creates a pop up with the correct number of input boxes.

xcoord = []
ycoord = []
x = []
y = []

for i in range(numofcoordiantes):
    xcoord[i] = ttk.Entry(mainframe, textvariable=x[i])
    ycoord[i] = ttk.Entry(mainframe, textvariable=y[i])

ttk.Button(mainframe, text="OK", command=lambda: function(xcoord, ycoord))

However, when I try to do the calculations I get the error:

TypeError: unsupported operand type(s) for -: 'Entry' and 'int'

If I print out the coordiantes they look like this:

[<tkinter.ttk.Entry object at 0x03EDF9B0>, <tkinter.ttk.Entry object at 0x03EDFA30>, <tkinter.ttk.Entry object at 0x03EDFAB0>]
[<tkinter.ttk.Entry object at 0x03EDF9D0>, <tkinter.ttk.Entry object at 0x03EDFA50>, <tkinter.ttk.Entry object at 0x03EDFAD0>]

None of my other input boxes give me this issue, so I'm not sure if this is a result of using a list. If so, could you please point me in an alternate direction?

Answer 1

You are storing references to the entry widgets in xcoord and ycoord , rather than the values of the entry widgets. You can remove the use of textvariable and get the values from the entry widgets like this:

x_coordinates = [int(widget.get()) for widget in xcoord]
y_coordinates = [int(widget.get()) for widget in ycoord]

Though, you'll get errors if any of the widgets are blank or have non-integers in them. You'll have to add some error handling code to take care of that.

If you are unfamiliar with list comprehensions, the first line of code above is simply shorthand for this:

x_coordinates = []
for widget in xcoord:            # for each widget in the list...
    s = widget.get()             # get string value
    value = int(s)               # convert to integer
    x_coordinates.append(value)  # append to the list of coordinates