Question

所以我试图编写一些代码，它接受两个用户输入的值，比较它们，然后告诉用户他/她是否输入了正确的值。（USL应该大于LSL，非常简单的标准）在这里你可以看到我如何从用户那里获得条目

    # get USL and LSL
    Label(self, text = "USL").grid(row = 5, column = 0, sticky = W, padx=5, pady=5)        
    self.e6 = Entry(self).grid(row = 5, column = 1)    
    Label(self, text = "LSL").grid(row = 6, column = 0, sticky = W, padx=5, pady=5)       
    self.e7 = Entry(self).grid(row = 6, column = 1)

下一段代码是我检查代码的地方

    # button to check USL is higher than LSL
    self.button = Button(self)
    self.button["text"] = "Check USL and LSL"
    self.button["command"] = self.check_limits
    self.button.grid(row = 6, column = 2, sticky = W, padx=5, pady=5)

最后我在这里定义了check_limits函数

    def check_limits(self):

    e6 = int(self.e6)
    e7 = int(self.e7)

    if e6 > e7:
        message = "Limits are good"
    else:
        message = "USL can't be less than LSL, please re-enter USL and LSL"

    self.text.delete(0.0, END)
    self.text.insert(0.0, message)

目前我将变量e6和e7强制为整数，但是当我这样做时，我得到一个错误，说int（）参数必须是字符串或数字，而不是＆＃34; NoneType＆＃34;。为什么在这种情况下它们会被定义为null而不是整数？

或者，如果我不强迫他们成为整数，那么我总是得到＆＃34; USL不能......＆＃34;，无论e6是大于还是小于比e7。为什么要这样做以及如何解决？

如果此问题的上下文需要其他任何代码，请查看我的整个代码

from Tkinter import *
class Application(Frame):
""" A SPC program that takes user input and saves the file """

def __init__(self,master):
    """ initializes the frame """
    Frame.__init__(self,master)
    self.grid()
    self.create_widgets()        


def create_widgets(self):
    """create widgets for user inputted data"""

    # get name
    Label(self, text = "First Name").grid(row = 0, column = 0, sticky = W, padx=5, pady=5)
    self.e1 = Entry(self).grid(row = 0, column = 1)

    Label(self, text = "Last Name").grid(row = 1, column = 0, sticky = W, padx=5, pady=5)
    self.e2 = Entry(self).grid(row = 1, column = 1)

    # get work order
    Label(self, text = "Work Order Number").grid(row = 2, column = 0, sticky = W, padx=5, pady=5)
    self.e3 = Entry(self).grid(row = 2, column = 1)

    # get todays date
    Label(self, text = "Todays Date").grid(row = 3, column = 0, sticky = W, padx=5, pady=5)
    self.e4 = Entry(self).grid(row = 3, column = 1)

    # get bubble number
    Label(self, text = "Bubble Number").grid(row = 4, column = 0, sticky = W, padx=5, pady=5)
    self.e5 = Entry(self).grid(row = 4, column = 1)

    # get USL and LSL
    Label(self, text = "USL").grid(row = 5, column = 0, sticky = W, padx=5, pady=5)        
    self.e6 = Entry(self).grid(row = 5, column = 1)    
    Label(self, text = "LSL").grid(row = 6, column = 0, sticky = W, padx=5, pady=5)       
    self.e7 = Entry(self).grid(row = 6, column = 1)


    # button to check USL is higher than LSL
    self.button = Button(self)
    self.button["text"] = "Check USL and LSL"
    self.button["command"] = self.check_limits
    self.button.grid(row = 6, column = 2, sticky = W, padx=5, pady=5)

    # creates a spot to dictate whether USL and LSL are correct
    self.text = Text(self, width = 35, height = 2, wrap = WORD)
    self.text.grid(row = 6, column = 3, sticky = W)

def check_limits(self):

    e6 = int(self.e6)
    e7 = int(self.e7)

    if e6 > e7:
        message = "Limits are good"
    else:
        message = "USL can't be less than LSL, please re-enter USL and LSL"

    self.text.delete(0.0, END)
    self.text.insert(0.0, message)








root = Tk()
root.title("SPC Input Program")
root.geometry("700x500")

app = Application(root)

root.mainloop()

Answer 1

你的问题是这个

self.e6 = Entry(self).grid(row = 5, column = 1)

如果要使用指定的窗口小部件，则无法打包，放置或网格化。你需要把它改成这个

self.e6 = Entry(self)
self.e6.grid(row = 5, column = 1)

由于网格分配，您获得NoneType。对于您不打算访问的标签和按钮等静态窗口小部件，这样做很好。但是当您想要获取或为窗口小部件赋值时，它需要是窗口小部件而不是widget.grid()

＆＃39; NoneType＆＃39; tkinter的问题

1 个答案: