从.txt文件中读取时间，然后倒计时到该时间

问题描述

我有一个名为sorted_passes.txt的文本文件，其内容如下：

NOAA18 23/08/2020 10:56:46最大海拔：67
NOAA19 23/08/2020 19:08:02最大海拔：74
NOAA15 23/08/2020 20:12:44最大海拔：87
NOAA18 23/08/2020 22:19:47最大海拔：90

我想让一个计时器执行以下任一操作：

在.txt文件中向下计数到下一次，然后在该时间之后，再次向下计数到下一次。
在.txt文件中倒数一次

我的计划是最终通过连接到树莓派的MAX7219 LED板显示倒数计时器。

到目前为止，我有以下python代码：

# calculate time until next pass

from datetime import datetime

futuredate = datetime.strptime('10:56:46','%H:%M:%s')
Nowdate = datetime.Now()
count = int((futuredate-Nowdate).total_seconds())
days = count//86400
hours = (count-days*86400)//3600
minutes = (count-days*86400-hours*3600)//60
seconds = count-days*86400-hours*3600-minutes*60

print("Next Pass: {}h:{}m:{}s".format(hours,minutes,seconds))

解决方法

这应该使您入门：

from datetime import datetime
from time import sleep

def compare(event):
    """Return True if it's counting down,false if the time already passed"""
    now = datetime.now()
    if now <= event:
        diff = event - now
        print("Countdown: {}".format(diff))
        return True
    else:
        return False


def extract_timestamp(line):
    """Extract datetime from string:
    NOAA18 23/08/2020 10:56:46 Max Elev: 67
    """
    time_stamp = line[7:][:-14]
    time_event = datetime.strptime(time_stamp,'%d/%m/%Y %H:%M:%S')
    return time_event

def open_file():
    with open('sorted_passes.txt','r') as f:
        return f.readlines()


data = open_file()

# iterate through the lines of the file
for line in data:
    ts = extract_timestamp(line)

    while compare(ts):
        sleep(1)
    else:
        print("Next event")
        continue
print("Finished")

这将打印一个倒计时语句，其中包含需要花费多长时间，一秒钟的睡眠时间。否则它将转到下一个事件，直到选中所有行。

您需要确保文件日期是递增的（例如，新行总是比之前的行晚）。

示例输出（我在最后一行中手动更改了日期）：

Next event
Next event
Next event
Countdown: 0:00:03.531014
Countdown: 0:00:02.526724
Countdown: 0:00:01.524277
Countdown: 0:00:00.518995
Finished

countdown python