Question

我有一项任务，我遇到了麻烦。代码可以工作，但我现在遇到的问题是让它变圆，我似乎无法找到放置“.2f”的正确位置。以及显示不使用数字或负数的错误。任何意见是极大的赞赏。

import tkinter

class MPG:
    def __init__(self):
        # create main window
        self.main_window = tkinter.Tk()

        # create four frames
        self.gallons_frame = tkinter.Frame(self.main_window)
        self.miles_frame = tkinter.Frame(self.main_window)
        self.mpg_frame = tkinter.Frame(self.main_window)
        self.button_frame = tkinter.Frame(self.main_window)


        self.gallons_label = tkinter.Label(self.gallons_frame, \
                                       text='Enter the number of gallons: ')
        self.gallons_entry = tkinter.Entry(self.gallons_frame, \
                                       width=10)
        self.gallons_label.pack(side='left')
        self.gallons_entry.pack(side='left')


        self.miles_label = tkinter.Label(self.miles_frame, \
                                           text='Enter the number of miles: ')
        self.miles_entry = tkinter.Entry(self.miles_frame, \
                                           width=10)
        self.miles_label.pack(side='left')
        self.miles_entry.pack(side='left')


        self.result_label = tkinter.Label(self.mpg_frame, \
                                       text='Miles Per Gallon')
        self.mpg = tkinter.StringVar() 
        self.mpg_label = tkinter.Label(self.mpg_frame, \
                                       textvariable=self.mpg)
        self.result_label.pack(side='left')
        self.mpg_label.pack(side='left')


        self.calc_button = tkinter.Button(self.button_frame, \
                                          text='Calculate MPG', \
                                          command=self.calc_mpg)
        self.quit_button = tkinter.Button(self.button_frame, \
                                          text='Quit', \
                                          command=self.main_window.destroy)
        self.calc_button.pack(side='left')
        self.quit_button.pack(side='left')


        self.gallons_frame.pack()
        self.miles_frame.pack()
        self.mpg_frame.pack()
        self.button_frame.pack()

    # the calc_mpg is the callback function for the calc_button
    def calc_mpg(self):
        # Get miles and gallons and store them in variables
        self.gallons = float(self.gallons_entry.get())
        self.miles = float(self.miles_entry.get())

        # calculate the MPG
        self.miles_per_gallon = self.miles / self.gallons

        # update the mpg_label
        self.mpg.set(str(round(self.miles_per_gallon)))

carmpg = MPG()

Answer 1

尝试使用内置函数round。另外，我认为你可能错过了一个int to string call。

# the calc_mpg is the callback function for the calc_button
def calc_mpg(self):
    # Get miles and gallons and store them in variables
    self.gallons = float(self.gallons_entry.get())
    self.miles = float(self.miles_entry.get())

    # calculate the MPG
    self.miles_per_gallon = self.miles / self.gallons

    # update the mpg_label
    self.mpg.set(str(round(self.miles_per_gallon, 2)))

每加仑gui程序python英里

1 个答案: