Python-如果文件中的字符串以16开头

Question

I have a script that checks my ip address on my PC and writes it to a file on my PC - This is working fine

import socket
import sys
import requests
import urllib.request
import shutil
import subprocess
from time import sleep
import os
from os import system

# URL for download
URL = 'https://here/app.exe'

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(('8.8.8.8', 1))
local_ip_address = s.getsockname()[0]
sys.stdout = open("C:\\Temp\\nw_check.txt", "w+")
print(s.getsockname() [0])

Now I would like to do this next

Check the file C:\\Temp\\nw_check.txt and if the IP address in that file starts with 116, 115, 117 then download the above app using a proxy I will set .. If it starts with anything else then proceed with download

if xxxxxx(xxxxxxxx()).startswith(('116', '115', '117')):
    r = requests.get(URL, stream=True, proxies={'http': 'http://proxy:6547', 'https': 'http://proxy:6547'})
else:
    r = requests.get(URL, stream=True)

Answer 1

sys.stdout = open("C:\\Temp\\nw_check.txt", "w+")

print(s.getsockname() [0])

Why are you setting the file to stdout then printing instead of just printing / writing directly to the file?

with open("C:\\Temp\\nw_check.txt", "w+") as f:
    print(s.getsockname()[0], file=f)
    # of f.write(str(s.getsockname()[0])); f.write('\n')

Check the file C:\\Temp\\nw_check.txt and if the IP address in that file starts with 116, 115, 117

Why are you going through an intermediate file? Why not just check the result of s.getsockname() [0] directly?

That aside: 1. if you're using the code above and are below the "with", or are in a different file, re-open the file in r mode, read the first 3 characters and check if that's what you're looking for:

with open("C:\\Temp\\nw_check.txt", "w+") as f:
    print(s.getsockname()[0], file=f)
with open(fname, 'r') as f:
    if f.read(3) in ('116', '115', '117'):
        # etc…

2. or 2 if you're using your original code or put that within the with body of the above, seek(0) to move the cursor back to the start of the file then read the first 3 characters and check.

sys.stdout.seek(0)
if f.read(3) in ('116', '115', '117'):
    # etc…

Answer 2

just open the file again and read the ip address:

with open("C:\\Temp\\nw_check.txt", "r") as ip_file:
    ip_address = ip_file.readline()

if ip_address.startswith(("115", "116", "117")):
        # and so on

Answer 3

Some variation of this to suit your needs should work:

with open("C:\\Temp\\nw_check.txt", "r") as input_file:
    for ip_address in input_file:
        if ip_address.startswith(("115", "116", "117")):
            r = requests.get(URL, stream=True, proxies={'http': 'http://proxy:6547', 'https': 'http://proxy:6547'})
        else:
            r = requests.get(URL, stream=True)

Since your file only has one line, the for loop will run just once and exit.