Python time.sleep() alternatives for fetching web content

Question

I'm writing a weather display program for my Raspberry Pi in python that fetches data using weather.com's api. As it stands, I have set it to sleep for 5 minutes after each main 'while' loop. This is because I don't want the Pi constantly using the wifi to fetch the same weather data. The problem with this is if I try to close or alter the program in any way, it waits to finish the time.sleep() function before continuing. I would like to add buttons to create a scroll menu but currently, the program will hang in that time.sleep() function before continuing. Is there an alternative I can use to delay the fetching of data while keeping program responsiveness?

It's not really clear what you're asking, you probably want to write up a [MCVE] that demonstrates the problems you're running into. — pvg, Dec 16 '16 at 05:56
You can decrease sleeping time to 1 sec and put it in a loop: 'for i in xrange(300): time.sleep(1)`. — Gennady Kandaurov, Dec 16 '16 at 05:57
`pygame` has `pygame.time` which you can use to check time and execute command in `while True` loop. — furas, Dec 16 '16 at 11:30

score 2 · Answer 1 · edited May 23 '17 at 11:45

You can do something like this:

import time, threading
def fetch_data():
    # Add code here to fetch data from API.
    threading.Timer(10, fetch_data).start()

fetch_data()

fetch_data method will be executed inside a thread so you wont have much problem. There is also a delay before calling the method. So you wont be bombarding the API.

Example source: Executing periodic actions in Python

underscoreC · Answer 2 · 2016-12-17T07:07:52.400

1

Create a timer with python's time module

import time

timer = time.clock()
interval = 300 # Time in seconds, so 5 mins is 300s

# Loop

while True:
    if timer > interval:
        interval += 300 # Adds 5 mins
        execute_API_fetch()

    timer = time.clock()

edited Dec 17 '16 at 07:07

answered Dec 16 '16 at 10:46

underscoreC

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it doesn't work - it waits 5 mins only once - not periodically – furas Dec 16 '16 at 12:09

furas · Answer 3 · 2016-12-16T11:56:03.597

Pygame has pygame.time.get_ticks() which you can use to check time and use it to execute function in mainloop.

import pygame

# - init -

pygame.init()

screen = pygame.display.set_mode((800, 600))

# - objects -

curr_time = pygame.time.get_ticks()

# first time check at once
check_time = curr_time

# - mainloop -

clock = pygame.time.Clock()

running = True

while running:

    # - events -

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_ESCAPE:
             running = False

    # - updates -

    curr_time = pygame.time.get_ticks()

    if curr_time >= check_time:
        print('time to check weather')

        # TODO: run function or thread to check weather

        # check again after 2000ms (2s)
        check_time = curr_time + 2000

    # - draws -
        # empty

    # - FPS -

    clock.tick(30)

# - end -

pygame.quit()

BTW: if fetching web content takes more time then run it in thread.

Python time.sleep() alternatives for fetching web content

3 Answers3