如何在 python 中为某个时间和日期制作倒数计时器？

Question

I'm working on a countdown timer for the next spacex launch with python and tkinter. The timer is supposed to end at 2020-05-30, 22:30 CEST. I want it to update for every second HOURS:MINUTES:SECONDS. I've tried but all i could come up with is this, which still gives me an error.

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

The immediate error is a missing closing parenthesis for str() on this line:

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

But while we're at it, let's use tkinter's own timing mechanism instead of a loop and sleep() , and use the time formatting functions that Python provides. And boost the font size:

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()

Using strftime() this way makes it only good for a month prior.