用python绘制七段数码管并实现秒表倒计时功能

首先，需要安装 Python 的 GUI 库 tkinter，可以使用以下命令：

pip install tkinter

然后，我们可以开始实现绘制七段数码管的功能。以下是代码实现：

import tkinter as tk

class SevenSegment(tk.Canvas):
    def __init__(self, master=None, cnf={}, **kw):
        super().__init__(master=None, cnf={}, **kw)
        self.configure(width=60, height=100, bg='black', highlightthickness=0)
        self.draw_segments([0, 0, 0, 0, 0, 0, 0])

    def draw_segments(self, segments):
        self.delete(tk.ALL)
        self.create_polygon(5, 5, 55, 5, 50, 10, 10, 10, fill='red' if segments[0] else 'grey', outline='')
        self.create_polygon(5, 5, 10, 10, 10, 50, 5, 55, fill='red' if segments[1] else 'grey', outline='')
        self.create_polygon(55, 5, 50, 10, 50, 50, 55, 55, fill='red' if segments[2] else 'grey', outline='')
        self.create_polygon(5, 55, 10, 50, 10, 90, 5, 95, fill='red' if segments[3] else 'grey', outline='')
        self.create_polygon(55, 55, 50, 50, 50, 90, 55, 95, fill='red' if segments[4] else 'grey', outline='')
        self.create_polygon(5, 95, 10, 90, 50, 90, 55, 95, fill='red' if segments[5] else 'grey', outline='')
        self.create_polygon(10, 50, 50, 50, 55, 55, 10, 55, fill='red' if segments[6] else 'grey', outline='')

这个类实现了一个七段数码管的绘制，接下来我们实现秒表倒计时的功能。

import time

class Stopwatch:
    def __init__(self, master):
        self.master = master
        self.seven_segment = SevenSegment(master, bg='black')
        self.seven_segment.grid(row=0, column=0, columnspan=3, padx=10, pady=10)
        self.start_button = tk.Button(master, text='Start', command=self.start)
        self.start_button.grid(row=1, column=0, padx=10, pady=10)
        self.stop_button = tk.Button(master, text='Stop', command=self.stop, state='disabled')
        self.stop_button.grid(row=1, column=1, padx=10, pady=10)
        self.reset_button = tk.Button(master, text='Reset', command=self.reset, state='disabled')
        self.reset_button.grid(row=1, column=2, padx=10, pady=10)
        self.running = False
        self.count = 0
        self.start_time = 0
        self.update()

    def start(self):
        self.running = True
        self.start_button.config(state='disabled')
        self.stop_button.config(state='normal')
        self.reset_button.config(state='disabled')
        self.start_time = time.time()

    def stop(self):
        self.running = False
        self.start_button.config(state='normal')
        self.stop_button.config(state='disabled')
        self.reset_button.config(state='normal')

    def reset(self):
        self.count = 0
        self.update()

    def update(self):
        if self.running:
            self.count = int(time.time() - self.start_time)
            if self.count < 0:
                self.count = 0
                self.running = False
                self.start_button.config(state='normal')
                self.stop_button.config(state='disabled')
                self.reset_button.config(state='normal')
            else:
                self.master.after(100, self.update)
        else:
            self.master.after(100, self.update)

        minutes = self.count // 60
        seconds = self.count % 60
        self.seven_segment.draw_segments([minutes // 10, minutes % 10, seconds // 10, seconds % 10, 0, 0, 0])

这个类实现了秒表倒计时的功能，并且生成了一个 GUI 界面，包含“Start”、“Stop”、“Reset”按钮和一个七段数码管。接下来我们可以将这个类实例化，生成一个秒表倒计时的窗口。

root = tk.Tk()
stopwatch = Stopwatch(root)
root.mainloop()

完整代码如下：

import tkinter as tk
import time

class SevenSegment(tk.Canvas):
    def __init__(self, master=None, cnf={}, **kw):
        super().__init__(master=None, cnf={}, **kw)
        self.configure(width=60, height=100, bg='black', highlightthickness=0)
        self.draw_segments([0, 0, 0, 0, 0, 0, 0])

    def draw_segments(self, segments):
        self.delete(tk.ALL)
        self.create_polygon(5, 5, 55, 5, 50, 10, 10, 10, fill='red' if segments[0] else 'grey', outline='')
        self.create_polygon(5, 5, 10, 10, 10, 50, 5, 55, fill='red' if segments[1] else 'grey', outline='')
        self.create_polygon(55, 5, 50, 10, 50, 50, 55, 55, fill='red' if segments[2] else 'grey', outline='')
        self.create_polygon(5, 55, 10, 50, 10, 90, 5, 95, fill='red' if segments[3] else 'grey', outline='')
        self.create_polygon(55, 55, 50, 50, 50, 90, 55, 95, fill='red' if segments[4] else 'grey', outline='')
        self.create_polygon(5, 95, 10, 90, 50, 90, 55, 95, fill='red' if segments[5] else 'grey', outline='')
        self.create_polygon(10, 50, 50, 50, 55, 55, 10, 55, fill='red' if segments[6] else 'grey', outline='')

class Stopwatch:
    def __init__(self, master):
        self.master = master
        self.seven_segment = SevenSegment(master, bg='black')
        self.seven_segment.grid(row=0, column=0, columnspan=3, padx=10, pady=10)
        self.start_button = tk.Button(master, text='Start', command=self.start)
        self.start_button.grid(row=1, column=0, padx=10, pady=10)
        self.stop_button = tk.Button(master, text='Stop', command=self.stop, state='disabled')
        self.stop_button.grid(row=1, column=1, padx=10, pady=10)
        self.reset_button = tk.Button(master, text='Reset', command=self.reset, state='disabled')
        self.reset_button.grid(row=1, column=2, padx=10, pady=10)
        self.running = False
        self.count = 0
        self.start_time = 0
        self.update()

    def start(self):
        self.running = True
        self.start_button.config(state='disabled')
        self.stop_button.config(state='normal')
        self.reset_button.config(state='disabled')
        self.start_time = time.time()

    def stop(self):
        self.running = False
        self.start_button.config(state='normal')
        self.stop_button.config(state='disabled')
        self.reset_button.config(state='normal')

    def reset(self):
        self.count = 0
        self.update()

    def update(self):
        if self.running:
            self.count = int(time.time() - self.start_time)
            if self.count < 0:
                self.count = 0
                self.running = False
                self.start_button.config(state='normal')
                self.stop_button.config(state='disabled')
                self.reset_button.config(state='normal')
            else:
                self.master.after(100, self.update)
        else:
            self.master.after(100, self.update)

        minutes = self.count // 60
        seconds = self.count % 60
        self.seven_segment.draw_segments([minutes // 10, minutes % 10, seconds // 10, seconds % 10, 0, 0, 0])

root = tk.Tk()
stopwatch = Stopwatch(root)
root.mainloop()