Python-iptables how to optimize code

Question

I am just learning python and have written some code to set iptables using the python-iptables library. The problem I'm running in to is that I had to rewrite a lot of the same lines of code over and over. I understand functions somewhat but not OOP. I'm thinking there is a better OOP way of writing this code but I can't get my head around it. Any pointers will be greatly appreciated. The code is below. ``` import iptc def dropAllInbound(): chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'INPUT') rule = iptc.Rule() rule.in_interface = 'eth+' rule.target = iptc.Target(rule, 'DROP') chain.insert_rule(rule) def allowLoopback(): chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'INPUT') rule = iptc.Rule() rule.in_interface = 'lo' rule.target = iptc.Target(rule, 'ACCEPT') chain.insert_rule(rule) def allowEstablishedInbound(): chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'INPUT') rule = iptc.Rule() match = rule.create_match('state') match.state = 'RELATED,ESTABLISHED' rule.target = i…

Accepted Answer

OOP is for maintaining the state of something. OOP is for some object that has both properties and methods to manipulate those properties.

```
class Chair(object):

MAX_WEIGHT = 300

def __init__(self):
        super().__init__()

self.weight = 5
        self.currentWeight = self.weight
        self.holding = None
        self.broken = False

def hold(self, item):
        self.holding = item
        self.currentWeight = self.weight + item.weight
        self.checkWeight()

def checkWeight(self):
        if self.holding.weight > self.MAX_WEIGHT:
            self.broken = True
            ...
```

Your code seems fine; rewriting the code just for OOP may be more work than it's worth. If you really want to use OOP you may wish to do something like below.

```
class Table(object):
    def __init__(self):
        self.chain = None
        self.rule = None
        self.match = None

def setInput(self):
        self.chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'INPUT')

def setOutput(self):
        self.chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), 'OUTPUT')

...

table = Table()
table.setInput()
...
```

Python-iptables how to optimize code

Solution

Problem