如何在python中为特定的时间和日期制作倒计时计时器？

Question

我正在用python和tkinter为下一次spacex发射制作倒计时。计时器应该在2020-05-30，22:30 CEST结束。我希望它每秒钟更新一次小时：分钟：秒。我试过了，但我能想到的就是这个，这仍然给我一个错误

import tkinter as tk
from datetime import datetime
import time

HEIGHT = 250
WIDTH = 1000

def timer():
    spacex = datetime(2020, 5, 30, 22 - 1, 30, 0).timestamp()
    dif = spacex - time.time()

    # H:M:S
    while (dif >= 0):
        dif = spacex - time.time()

        textline = str(dif // 3600)[:2] + ":" + str((dif // 60) % 60)[:2] + ":" + str((dif // 1) % 60[:2]
        time.sleep(1)

        v = str(textline)
        label["text"] = v

# TKINTER BELOW
root = tk.Tk()

canvas = tk.Canvas(root, height=HEIGHT, width=WIDTH)
canvas.pack()

frame = tk.Frame(root, bg="#808080", bd=20)
frame.place(relwidth=0.6, relheight=0.4, relx=0.2, rely=0.25)

button = tk.Button(root, text="See timer!", font="Arial", command=lambda: timer())
button.place(relheight=0.1, relwidth=0.1)

label = tk.Label(frame, font="Arial")
label.place(relwidth=1, relheight=1)

root.mainloop()

Answer 1

直接错误是此行str()缺少右括号：

... + str((dif // 1) % 60[:2]

但是，当我们进行此操作时，让我们使用tkinter自己的计时机制，而不是循环和sleep()，并使用Python提供的时间格式化函数。并增加字体大小：

import tkinter as tk
from datetime import datetime
import time

WIDTH, HEIGHT = 1000, 250

def timer():
    space_x = datetime(2020, 5, 30, 22 - 1, 30, 0).timestamp()
    delta = space_x - time.time()

    if delta >= 0:
        label["text"] = time.strftime("%d day(s), %H:%M:%S", time.localtime(delta))

        root.after(1000, timer)

root = tk.Tk()

canvas = tk.Canvas(root, height=HEIGHT, width=WIDTH)
canvas.pack()

frame = tk.Frame(root, bg="#808080", bd=20)
frame.place(relwidth=0.6, relheight=0.4, relx=0.2, rely=0.25)

button = tk.Button(root, text="See timer!", font="Arial", command=timer)
button.place(relheight=0.1, relwidth=0.1)

label = tk.Label(frame, font=("Arial", "24", "bold"))
label.place(relwidth=1, relheight=1)

root.mainloop()

这样使用strftime()只会使它在前一个月有效