Python请求的行为就像它具有缓存一样

Question

I am trying to get a color hexcode from an XML page on my website and update a script within 5-10 seconds. I am able to read the hexcode just fine, and I am able to change the value in the XML file just fine, but the script takes awhile to reflect the update.

I want the script to update every 5 seconds by checking the XML file from my webserver, however it takes about 1 full minute before the code actually sees the update. Is my python script somehow caching the XML file? Is my webserver possibly sending a cached version? (Viewing the XML file in chrome refreshes instantly though.)

Python code:

import time
import serial
import requests
from bs4 import BeautifulSoup

ser = serial.Serial('/dev/ttyACM0',9600)
print('Connected to Arduino!')

while (True):
    print('Connecting to website...')

    page = requests.get('http://xanderluciano.com/pi/color.xml', timeout=5)
    soup = BeautifulSoup(page.text, 'html.parser')

    print('scraped hexcode: ' + soup.color.string)

    hex = soup.color.string
    ser.write(hex.encode('utf-8'))
    print(ser.readline())

    time.sleep(5);

XML File:

<?xml version="1.0" encoding="UTF-8"?>
<ledstrip>
    <color>2196f3</color>
    <flash>false</flash>
    <freq>15</freq>
</ledstrip>

Answer 1

The solution was that my webserver used NGINX as a server side cache controller, I opted to disable this cache control during the development stage, just so that I could see the results instantly. Most likely there is a better way of pushing data rather than continually polling the webserver for it.