Python3 请求总是返回相同的请求

Question

I'm making a cryptocurrency watch app. I using for this requests but i always taking same requests.

coin_list = ["bitcoin", "ethereum", "bittorrent", "xrp", "dogecoin"]

while(True):
    for coin in coin_list:
        print(BeautifulSoup.get_text(BeautifulSoup(requests.get('https://www.coindesk.com/price/'+coin).content, 'html.parser').find('div', {'class': 'price-large'}))[1:])

this script returning it to me:

36,331.66
2,219.07
0.002826
0.716486
0.266623
36,331.66
2,219.07
0.002826
0.716486
0.266623
36,331.66
2,219.07
0.002826
0.716486
0.266623
36,331.66
2,219.07
0.002826
0.716486
0.266623
36,331.66
2,219.07
0.002826
0.716486
0.266623
36,331.66
2,219.07
0.002826

this is not about cache. i was try it with headers.

Answer 1

Well, you're doing:

while(True):
    ...

which means that you are forever going to loop over coin_list since this condition is always True .

Here's an example in action of what is happening. (I have refactored your code for readability):

while True:
    for coin in coin_list:
        soup = BeautifulSoup(
            requests.get("https://www.coindesk.com/price/" + coin).content, "html.parser"
        )
        print(soup.find("div", {"class": "price-large"}).text)

    # The following will run after entirely looping over `coin_list`, we are still in the `while` loop
    print("Finished looping over `coin_list`")
    print()
    

Output:

$36,294.89
$2,213.96
$0.002825
$0.721100
$0.267331
Finished looping over `coin_list`

$36,294.89
$2,213.96
$0.002825
$0.721100
$0.267331
Finished looping over `coin_list`
...
... And on forever

So, to fix this, just remove the while condition, and loop over coin_list :

import requests
from bs4 import BeautifulSoup


coin_list = ["bitcoin", "ethereum", "bittorrent", "xrp", "dogecoin"]

for coin in coin_list:
    soup = BeautifulSoup(
        requests.get("https://www.coindesk.com/price/" + coin).content,
        "html.parser",
    )
    print(soup.find("div", {"class": "price-large"}).text)

Output:

$36,294.89
$2,216.34
$0.002825
$0.721100
$0.267331