How can I see if there's an available and active network connection in Python?

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I want to see if I can access an online API, but for that, I need to have Internet access.

How can I see if there's a connection available and active using Python?

22 Answers

Here's my version

import requests

try:
    if requests.get('https://google.com').ok:
        print("You're Online")
except:
    print("You're Offline")

A modern portable solution with requests:

import requests

def internet():
    """Detect an internet connection."""

    connection = None
    try:
        r = requests.get("https://google.com")
        r.raise_for_status()
        print("Internet connection detected.")
        connection = True
    except:
        print("Internet connection not detected.")
        connection = False
    finally:
        return connection

Or, a version that raises an exception:

import requests
from requests.exceptions import ConnectionError

def internet():
    """Detect an internet connection."""

    try:
        r = requests.get("https://google.com")
        r.raise_for_status()
        print("Internet connection detected.")
    except ConnectionError as e:
        print("Internet connection not detected.")
        raise e

Taking Ivelin's answer and add some extra check as my router delivers its ip address 192.168.0.1 and returns a head if it has no internet connection when querying google.com.

import socket

def haveInternet():
    try:
        # first check if we get the correct IP-Address or just the router's IP-Address
        info = socket.getaddrinfo("www.google.com", None)[0]
        ipAddr = info[4][0]
        if ipAddr == "192.168.0.1" :
            return False
    except:
        return False

    conn = httplib.HTTPConnection("www.google.com", timeout=5)
    try:
        conn.request("HEAD", "/")
        conn.close()
        return True
    except:
        conn.close()
        return False

This works for me in Python3.6

import urllib
from urllib.request import urlopen


def is_internet():
    """
    Query internet using python
    :return:
    """
    try:
        urlopen('https://www.google.com', timeout=1)
        return True
    except urllib.error.URLError as Error:
        print(Error)
        return False


if is_internet():
    print("Internet is active")
else:
    print("Internet disconnected")

I added a few to Joel's code.

    import socket,time
    mem1 = 0
    while True:
        try:
                host = socket.gethostbyname("www.google.com") #Change to personal choice of site
                s = socket.create_connection((host, 80), 2)
                s.close()
                mem2 = 1
                if (mem2 == mem1):
                    pass #Add commands to be executed on every check
                else:
                    mem1 = mem2
                    print ("Internet is working") #Will be executed on state change

        except Exception as e:
                mem2 = 0
                if (mem2 == mem1):
                    pass
                else:
                    mem1 = mem2
                    print ("Internet is down")
        time.sleep(10) #timeInterval for checking

For my projects I use script modified to ping the google public DNS server 8.8.8.8. Using a timeout of 1 second and core python libraries with no external dependencies:

import struct
import socket
import select


def send_one_ping(to='8.8.8.8'):
   ping_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.getprotobyname('icmp'))
   checksum = 49410
   header = struct.pack('!BBHHH', 8, 0, checksum, 0x123, 1)
   data = b'BCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwx'
   header = struct.pack(
      '!BBHHH', 8, 0, checksum, 0x123, 1
   )
   packet = header + data
   ping_socket.sendto(packet, (to, 1))
   inputready, _, _ = select.select([ping_socket], [], [], 1.0)
   if inputready == []:
      raise Exception('No internet') ## or return False
   _, address = ping_socket.recvfrom(2048)
   print(address) ## or return True


send_one_ping()

The select timeout value is 1, but can be a floating point number of choice to fail more readily than the 1 second in this example.

import requests and try this simple python code.

def check_internet():
    url = 'http://www.google.com/'
    timeout = 5
    try:
        _ = requests.get(url, timeout=timeout)
        return True
    except requests.ConnectionError:
        return False

Make sure your pip is up to date by running

pip install --upgrade pip

Install the requests package using

pip install requests  
    import requests
    import webbrowser
    url = "http://www.youtube.com"

    timeout = 6
    try:
        request = requests.get(url, timeout=timeout)
        print("Connected to the Internet")
        print("browser is loading url")
        webbrowser.open(url)
    except (requests.ConnectionError, requests.Timeout) as exception:
       print("poor or no internet connection.")

I just want to refer to Ivelin's solution, because I can't comment there.

In python 2.7 with an old SSL certificate (in my case, not possible to update, which is another story), there is a possibility of a Certificate Error. In that case, replacing '8.8.8.8' with 'dns.google' or '8888.google' can help.

Hope this will someone helps too.

try:
    import httplib  # python < 3.0
except:
    import http.client as httplib


def have_internet():
    conn = httplib.HTTPSConnection("8888.google", timeout=5)
    try:
        conn.request("HEAD", "/")
        return True
    except Exception:
        return False
    finally:
        conn.close()
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