Could someone look over this and let me know if i’ve butchered anything. It’s just a simple class definition in python, but I don’t have any local devs to make sure I’m using the language right. Using ‘self’ so much feels awkward and I don’t know if it is needed.
import time
import pexpect
from datetime import datetime
import deviceModelconfigs
from kafka import KafkaClient, KeyedProducer, HashedPartitioner, RoundRobinPartitioner
class Device():
def __init__(self, roomName, ip, model):
self.model = model
self.ip = ip
self.roomName = roomName
self.codes = deviceModelconfigs.setCodes(self.model)
self.powerStatus = 'na'
self.signalStatus = 'na'
self.networkStatus = 'na'
def connect(self):
self.child = pexpect.spawn('telnet '+ self.ip + ' 2001')
def sendMessage(self):
print ("devices", self.roomName, str("{"timestamp":"" + str(datetime.utcnow().isoformat()) +
"","roomName":""+ self.roomName +
"","powerStatus":""+ self.powerStatus +
"","signalStatus"""+ self.signalStatus +
"","networkStatus":""+ self.networkStatus +
"","deviceModel":""+ self.model +
"","deviceType":""+ self.codes['deviceType'] + ""}"))
def testPower(self):
try:
self.child.sendline(self.codes['pwrStCmd'])
self.child.expect(self.codes['pwrStOnRe'], timeout=5)
status = 'on'
except:
try:
self.child.sendline(self.codes['pwrStCmd'])
self.child.expect(self.codes['pwrStOffRe'], timeout=5)
status = 'off'
except:
status = 'na'
return status
def testAll(self):
self.powerStatus = Device.testPower(self)
Device.sendMessage(self)
self.child.terminate(True)
jeff = Device('FM1-200','10.1.174.12','WD510U')
jeff.connect()
jeff.testAll()
2
You need self when you want to refer to the instance of a class within the class itself.
For example, an instance method can call other instance methods or properties or use instance fields.
If you have used other object oriented languages, you may have a habit of using this. Python’s self is similar (while not identical) to this in other languages.
The usage of self in your sample code looks correct.
Note that:
-
You may consider replacing strings like
"{"timestamp":""by the more readable'{"timestamp":"'. -
Consider using string formatting. Two most popular ways to format strings in Python is
%and.format. If you are unsure which one should you use, this answer on Stack Overflow may help. -
You use strings to describe statuses. While this is an acceptable approach, you may also be interested in Python’s enums.
-
You import four types from
kafka. Have you considered using justimport kafka? This answer on Programmers.SE explains the difference betweenimportandfrom ... import. -
In
testPower, you have code duplication. Consider extracting lines containingsendlineandexpectstatements in a separate method.