验证 Tkinter 输入框 [英] Validating Tkinter Entry Box

问题描述

我正在尝试验证我的输入框，它只接受浮点数、数字和运算符(+×÷-，%).但是我的程序只接受数字而不接受符号.

I am trying to validate my entry box, that only accepts floats, digits, and operators (+×÷-, %). But my program only accepts numbers not symbols.

我认为是我的条件或 Python 正则表达式有问题.

I think it is a problem with my conditions or Python Regex.

代码如下:

from tkinter import *
import re

root = Tk()
def correct(inp):
    pattern = re.compile(r'^(\d*\.?\d*)$')
    if pattern.match(inp) is not None:
        return True
    elif inp is "":
        return True
    else:
        return False

a = Entry(root)
e = root.register(correct)
a.config(validate='key', validatecommand=(e, '%P'))
a.pack()

root.mainloop()

推荐答案

您的正则表达式仅匹配浮点数:\d*.?\d* 匹配数字后跟可选的点和更多数字.如果你想匹配的是像[float][operator][float]这样的模式，那么你可以使用(只需在方括号中添加你想要的运算符):

Your regexp only matches floats: \d*.?\d* matches digits followed optionally by a dot and more digits. If what you want to match is a pattern like [float][operator][float], then you can use (just add the operators you want in the square brackets):

pattern = re.compile(r'^\d*\.?\d*[+*/\-%]?\d*\.?\d*$')

如果您不关心顺序而只想允许任何数字和运算符序列:

If you don't care about the order and just want to allow any sequence of numbers and operators:

pattern = re.compile(r'^[\d.+*/\-%]*$')

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