要对标签小部件中的所有文本加下划线，您需要创建一个新字体，该字体的underline属性设置为True。下面是一个例子：

try:
    import Tkinter as tk
    import tkFont
except ModuleNotFoundError:  # Python 3
    import tkinter as tk
    import tkinter.font as tkFont

class App:
    def __init__(self):
        self.root = tk.Tk()
        self.count = 0
        l = tk.Label(text="Hello, world")
        l.pack()
        # clone the font, set the underline attribute,
        # and assign it to our widget
        f = tkFont.Font(l, l.cget("font"))
        f.configure(underline = True)
        l.configure(font=f)
        self.root.mainloop()

if __name__ == "__main__":
    app = App()

对于那些在Python 3上工作并且不能让下划线工作的人，这里有一些示例代码可以让它工作。

from tkinter import font

# Create the text within a frame
pref = Label(checkFrame, text = "Select Preferences")
# Pack or use grid to place the frame
pref.grid(row = 0, sticky = W)
# font.Font instead of tkFont.Fon
f = font.Font(pref, pref.cget("font"))
f.configure(underline=True)
pref.configure(font=f)

一个人

mylabel = Label(frame, text = "my label", font="Verdana 15 underline")

试试下面这个：

mylbl=Label(Win,text='my Label',font=('Arial',9,'bold','underline'))
mylbl.grid(column=0,row=1)

mylabel = Label(frame, text = "my label")
mylabel.configure(font="Verdana 15 underline")

p = Label(root, text=" Test Label", bg='blue', fg='white', font = 'helvetica 8 underline')

把你自己的字体（我选择Helvetica 8）

要给所有字符加下划线，你应该导入tkinter。字体和使您自己的字体风格与此.举例来说-

from tkinter import *
from tkinter.font import Font
rt=Tk()
myfont=Font(family="Times",size=20,weight="bold", underline=1)
Label(rt,text="it is my GUI".title(),font=myfont,fg="green").pack()
rt.mainloop()

应该是这样的格式：
dev_label=Label(Right_frame, text="purxxx@gmail.com", font=("Times",15,"bold italic underline"), fg="black",bg="white")
dev_label.place(x=80,y=120)