如何停止一个程序每天运行多次？

Question

I want to prevent my program from running and accepting input more than once a calendar day. Is there a way to do this?

I tried importing the date at the end of my code and storing it in variable and then importing the date at the start of the code and comparing them but of course, the variable at the end of the code is not defined when you run the code for the first time.

import datetime

new_time = str(datetime.datetime.now())
new_time = new_time[8:10]
new_time = int(new_time)

while new_time == last_time:
    print("Please wait until tomorrow before entering a new value")





last_time = str(datetime.datetime.now())

last_time = last_time[8:10]
last_time = int(last_time)

With this approach, it works except for the first time when the variable last_time is not defined

Answer 1

By appending the current date into a file, you can compare the calendar day difference.

Code:

import datetime
new_day = int(datetime.datetime.now().strftime("%d"))
last_day = 0
with open("last_time.txt", "r") as f:
    lines = f.read().splitlines()
    last_day = lines[-1]

if new_day == int(last_day):
    print("Please wait until tomorrow before entering a new value")

with open("last_day.txt", "a+") as f:
    last_day = datetime.datetime.now().strftime("%d")
    f.write(last_day)

Explanation:

1. Create a text file(last_time.txt) and give the default day as when you are running the script for first time(as today(24))
2. get the new_day as day from datetime.now() and convert into an integer.
3. By default keeping the last_day=0 or you can give the current date for first time
4. Reading the last time from the last line of the file
5. If new_day and last_day are equal, then print the message to the user.
6. Fetch the current day as last_day and write to a file in append mode.

File O/p:

23
24

O/P:

Please wait until tomorrow before entering a new value