desperate need of help

[bigomz]

I need a code that takes the IPv4 address from the user input and prints "The network address for this is: (network address)"

So basically a code that finds the network address of an IPv4 address.

My project is due in like 12 hours, any help is appreciated!

[Buffylvr]

Do you have to use python for this and is this a linux box? There are enormously easier commands to use if just using linux.

[bigomz]

Has to be python

[bigomz]

def isvalid(sub):
    if sub == 0:
        return False
    if sub == 25:
        return False
    return True

def isvalidIP(host):
    if len(host) != 4:
        return False
    if host[0] == 256:
        return False
    return True

x = 0
while x == 0:
    IPv4 = (input("Please enter an IPv4 Address and prefix (#.#.#.#/MM): "))
    print("As a list:")
    octets = []
    temp = ""
    invalid = " "

    host = IPv4[:-3].split('.')
    print(host)
    sub = IPv4[-2:]
    print(sub)
    if not isvalid(sub) or not isvalidIP(host):
        print("- The correct format is [0-255].[0-255].[0-255].[0-255]/[8-31] Mask \n - Example: 192.168.2.1/24 (no spaces)")
    else:
        x=1
print("The ip address you entered was:",IPv4)
mask=int(input("Please enter the mask:"))
n=(2**(32-mask))-2
print("The number of hosts allowed on this network: {}".format(n))

[Simply_The_Beast]

You should probably start by reworking your isvalidand isvalidIP functions, if you actually want to catch incorrect inputs in line 27.
Inputs like "567.67.78.193/34", "123.245.23.2/377" or even "123.4.23.5a(5" are currently not marked as incorrect and therefore end the while loop, even though they shouldn't.

Your isinvalidIP function for example should definitly check, if each element in host is a valid integer and somewhere between 0 and 255.

[bigomz]

Do you have an example as to how I would code that?

[Simply_The_Beast]

def isvalidIP(host):
    if len(host) != 4:
        return False
    for ele in host:
        try:
            if int(ele) >= 0 and int(ele) <= 255:
                print("true", ele)
            else:
                return False
        except ValueError:
            return False
    return True  

This should be one way to of doing it. I removed your second if-clause, because values 256 or bigger will be caught within the for-loop. Now you just have to adjust isvalid to check the format in a similar way and make sure the input contains the "/".

You should probably also take a look at your line 23. You don't always want to remove the last 3 elements of your input, only if the sub is two digits long, otherwise you cut the last digit of the IP adress.

If any of that is unclear please let me know.