Question

我想获得两个单独的条目小部件来添加其中的内容，但现在的问题是它是连接条目小部件中的数字。

from tkinter import *

master = Tk()

class MainWindow:
    def __init__(self, master):
        self.master = master
        master.geometry("640x480")


def Calculate():
    entry1 = firstEntry.get()
    entry2 = secondEntry.get()
    result = entry1 + entry2
    print(result)


firstLabel = Label(text="First Value")
firstLabel.grid(row=1, column=1)

firstEntry = Entry(master)
firstEntry.grid(row=1, column=2)

addLabel = Label(text="+")
addLabel.grid(row=1, column=3)

secondEntry = Entry(master)
secondEntry.grid(row=1, column=4)

secondLabel = Label(text="Second Value")
secondLabel.grid(row=1, column=5)

equalsButton = Button(text="=", width=10, command=Calculate)
equalsButton.grid(row=2, column=3)

master.mainloop()

Answer 1

from tkinter import *

master = Tk()

class MainWindow:
    def __init__(self, master):
        self.master = master
        master.geometry("640x480")


def Calculate():
    entry1 = firstEntry.get()
    entry2 = secondEntry.get()
    result = int(entry1) + int(entry2)
    print(result)


firstLabel = Label(text="First Value")
firstLabel.grid(row=1, column=1)

firstEntry = Entry(master)
firstEntry.grid(row=1, column=2)

addLabel = Label(text="+")
addLabel.grid(row=1, column=3)

secondEntry = Entry(master)
secondEntry.grid(row=1, column=4)

secondLabel = Label(text="Second Value")
secondLabel.grid(row=1, column=5)

equalsButton = Button(text="=", width=10, command=Calculate)
equalsButton.grid(row=2, column=3)

master.mainloop()

只需通过int（firstentry.get（））和int（secondentry.get（））对entry.get的结果进行类型转换，否则会导致添加字符串

＆＃34; 4＆＃34; +＆＃34; 5＆＃34; =＆＃34; 45＆＃34;

Answer 2

问题在于，Python中的+运算符具有字符串和数字（以及其他）的含义。对于数字，它代表了自然（在＃34;常见＆＃34;意义上）添加：

>>> 1 + 1
2

另一方面，对于字符串，它代表串联：

>>> "Hello" + ", world!"
'Hello, world!"

get实例的tkinter.Entry方法返回一个字符串对象，即str的实例。因此，entry1 = firstEntry.get()和entry2 = secondEntry.get()都会为您提供一个字符串，无论输入是否包含数字。然后，entry1 + entry2会生成一个字符串，即entry1和entry2的串联。

因此，您需要事先将条目的内容转换为整数或浮点数，后者更为通用。您的Calculate功能可能会变为：

def Calculate():
    entry1 = float(firstEntry.get())
    entry2 = float(secondEntry.get())
    result = entry1 + entry2
    print(result)

但请注意，如果无法执行转换，float函数将引发ValueError。以下将更加谨慎：

def Calculate():
    try:
        entry1 = firstEntry.get()
        entry2 = secondEntry.get()
        result = entry1 + entry2
        print(result)
    except ValueError:
        print("Please type in valid numbers")

Python - 如何获取条目小部件而不是连接？

2 个答案: