[CentralOH] Help with learning how to use a class (please don't laugh :) )

[Eric Lake]

Using:

        self.disks = [disk for disk in self.server.Win32_LogicalDisk()]
        self.localDisks = [ disk for disk in self.disks if disk.DriveType == 3]

would then get the disk information every time I call the class though
wouldn't it? What I am trying to write is a general purpose class that
I can use to get all kinds of information from my servers. I have
removed the input and output file stuff. here is the class as it
stands currently:

import string
import wmi

class SysInfo(object):
    def __init__(self, hostname):
        self.host = hostname
        self.server = wmi.WMI(self.host)

    def GetLocalDrives(self):
        driveList = []
        for disk in self.server.Win32_LogicalDisk():
            if disk.DriveType == 3:
                driveList.append(str(disk.Name))
        return driveList

    def GetTotalDiskSpace(self, drive):
        self.drive = drive
        for disk in self.server.Win32_LogicalDisk():
            if disk.Name == self.drive:
                total = long(disk.Size) /1073741824.0
        return total

    def GetFreeDiskSpace(self, drive):
        self.drive = drive
        for disk in self.server.Win32_LogicalDisk():
            if disk.Name == self.drive:
                free = long(disk.FreeSpace) /1073741824.0
        return free

    def GetUsedDiskSpace(self, drive):
        self.drive = drive
        total = self.GetTotalDiskSpace(self.drive)
        free = self.GetFreeDiskSpace(self.drive)
        used = (total - free)
        return used

    def GetCpuList(self):
        cpulist = []
        cpudict = {}
        for cpu in self.server.Win32_Processor():
            name = string.strip(str(cpu.Name))
            deviceid = str(cpu.DeviceID)
            cpudict = {deviceid:name}
            cpulist.append(cpudict)
        return cpulist

    def GetNumCpu(self):
        cpus = self.GetCpuList()
        return len(cpus)

    def GetNodeName(self):
        # This is for when you are looking at a clustered env and
        # want to know who the active node is.
        for os in self.server.Win32_OperatingSystem():
            activeNode = os.CSName
        return str(activeNode)


On Wed, Jul 9, 2008 at 12:06 PM, Brian Costlow <brian.costlow at gmail.com> wrote:
> Eric,
>
> A couple of other things I noticed.
>
> You use one of these two constructs in all the methods.
>
> for disk in server.Win32_LogicalDisk():
>
> for disk in server.Win32_LogicalDisk():
>     if disk.DriveType == 3:
>
> Since it doesn't seem these would change for this script between the object
> creation and calling the methods, I'd refactor them into the init as well.
>
> class SysInfo(object):
>     def __init__(self, hostname):
>         self.host = hostname
>         server = wmi.WMI(self.host)
>         self.disks = [disk for disk in server.Win32_LogicalDisk()]
>         self.localDisks [ disk for disk in self.disks if disk.DriveType ==
> 3]
>
> Then you can iterate the lists in your methods.
>
>     def GetStorage(self):
>         for disk in self.localDisks:
>
> Also, it won't matter much in a one-pager, but if you were doing anything
> bigger, this might bite you. It looks like you're creating a global variable
> for the outfile, then referring to that implicitly from inside an object
> method. Typically, Id try to open/close that resource inside the method that
> uses it. If it had to come from outside, Id pass it explicitly just so the
> code was clearer.
>



-- 
Thanks,

Eric Lake