如何从 Python 中的对象数组访问对象

Question

I have made a object called Protocol that takes in a port and protocol name. This object is then stored in an array. My question is how do i access my object in the array? Im coming from mostly doing Java and I can't quite figure it out. I keep getting error 'int' object has no attribute getPort.

Protocol.py Object/Model

class Protocol:
    def __init__(self, protocolName, port):
         self.protocolName = protocolName
         self.port = port

    def setPort(self, port):
        self.port = port

    def setProtocol(self,protocolName):
        self.protocolName = protocolName

    def getPort(self):
        return self.port

    def getProtocol(self):
        return self.protocolName

JSONSlicer.py Where function is

from Model.Protocol import Protocol
from Model.Service import Service


class JSONSlicers:
    def protocolSeperator(self,protocols,num):
        protocolsFound = []   # Protocol port # odds, Protocol name # evens

        i=0
        for p in protocols:
            for sub in range(0,len(p.split('/')) - 1):
                #  protocol = Protocol(p.split('/')[sub])
                fPort = p.split('/')[sub]

                sub+=1
                fProto = p.split('/')[sub]
                #protocol = Protocol(p.split('/')[sub])
                protocol = Protocol(fPort,fProto)
                protocolsFound.append(protocol)

        print(protocolsFound[0].getPort()) # Trying to print attribute of object here

        return protocolsFound

Answer 1

In Python, you don't have to declare a variable before using it.

The line:

protocolsFound = [num]

Is probably intended to create a list of size num , but you can either just create it as an empty list protocolsFound = [] and start filling it with .append() , or if you need to be able to access specific positions in the list, you can create a list with num empty positions like protocolsFound = [None for _ in range(num)] . This is rarely needed in well-written Python code, though.

Answer 2

It errors because you set the first index of protocolsFound to an in num
Take a look at this line an fix it,

protocolsFound = [num]

why do you need the num in there?