I want to write Datetime every second in while loop , but it writes one time twice because of the loop .
Note : I don't want to use time.sleep() cause it would make the whole while loop effected.
The Example of my problem in a text file :
register : user 1 at 13:30:34
register : user 1 at 13:30:34
Please try this and use file write accordingly
import datetime
start_time = datetime.datetime.now()
print(start_time)
while True:
if (datetime.datetime.now() - start_time).seconds == 1:
start_time = datetime.datetime.now()
print(start_time)
Try this code !
You can use the gmtime to print the time & for every second delay you can use the sleep() function by importing time library.
from time import gmtime, strftime
import time
while True:
print(strftime("%H:%M:%S", gmtime()))
time.sleep(1)
Output :
11:10:23
11:10:24
11:10:25
11:10:26
11:10:27
11:10:28
11:10:29
11:10:30
If I got the point, you want to append time each second while the rest of code is running.
To achieve that you better to make a thread. The Multi Threading lets you to run your code while you're using sleep() withing your code.
There are many ways in which you could receive the desired effect, but to start off we need a function that we can call.
def save_datetime(file='date.txt', user=getpass.getuser()):
with open(file, 'a+') as f:
f.write('register: ' + user + '\t' + str(datetime.datetime.now().time()) + '\n')
We now need a function for the loop.
def threadingtime_every_sec(sec=60):
import threading, time
def loop():
while True:
save_datetime()
time.sleep(sec)
threading.Thread(target=loop).start()
I understand you don't want to use time.sleep() but because it runs a thread it isn't noticeable and so is run separately. The full script would be:
import datetime
import getpass
import threading
import time
def save_datetime(file='date.txt', user=getpass.getuser()):
with open(file, 'a+') as f:
f.write('register: ' + user + '\t' + str(datetime.datetime.now().time()) + '\n')
def threadingtime_every_sec(sec=60):
def loop():
while True:
save_datetime()
time.sleep(sec)
threading.Thread(target=loop).start()
if __name__ == '__main__':
threadingtime_every_sec(1)
I would thoroughly recommend this answer and this question as it gives you multiple ways - and a much better threading system using the Timer function and a Class. The full script in your case would be:
import threading
import time
import getpass
import datetime
class RepeatedTimer(object):
def __init__(self, interval, function, *args, **kwargs):
self._timer = None
self.interval = interval
self.function = function
self.args = args
self.kwargs = kwargs
self.is_running = False
self.next_call = time.time()
self.start()
def _run(self):
self.is_running = False
self.start()
self.function(*self.args, **self.kwargs)
def start(self):
if not self.is_running:
self.next_call += self.interval
self._timer = threading.Timer(self.next_call - time.time(), self._run)
self._timer.start()
self.is_running = True
def stop(self):
self._timer.cancel()
self.is_running = False
def save_datetime(file='date.txt', user=getpass.getuser()):
with open(file, 'a+') as f:
f.write('register: ' + user + '\t' + str(datetime.datetime.now().time()) + '\n')
if __name__ == '__main__':
RepeatedTimer(1, save_datetime)
This creates an example text file like this:
register: james 11:51:54.988595
register: james 11:51:55.988939
register: james 11:51:56.988767
If you don't want milliseconds replace str(datetime.datetime.now().time()) with datetime.datetime.now().strftime('%H:%M:%S').
input
import datetime,time
while True:
current_time = datetime.datetime.now()
print(current_time)
time.sleep(1)
output
2022-02-18 04:39:56.781569
2022-02-18 04:39:57.782559
2022-02-18 04:39:58.783791
2022-02-18 04:39:59.785152
2022-02-18 04:40:00.785640
2022-02-18 04:40:01.786961
2022-02-18 04:40:02.788185
2022-02-18 04:40:03.788571
2022-02-18 04:40:04.789626
2022-02-18 04:40:05.790575
2022-02-18 04:40:06.791805
2022-02-18 04:40:07.793075
2022-02-18 04:40:08.794314
2022-02-18 04:40:09.795562
