On May 3, 10:52 pm, Mike <[EMAIL PROTECTED]> wrote:
> I was messing around with adding methods to a class instance at
> runtime and saw the usual code one finds online for this. All the
> examples I saw say, of course, to make sure that for your method that
> you have 'self' as the first parameter. I got to thinking and thought
> "I have a lot of arbitrary methods in several utility files that I
> might like to add to things. How would I do that?" And this is what I
> came up with:
>
> def AddMethod(currObject, method, name = None):
> if name is None: name = method.func_name
> class newclass(currObject.__class__):pass
> setattr(newclass, name, method)
> return newclass()
>
> And lets say I have a utility function that can check if a drive
> exists on my windows box called HasDrive. I can add that like this:
>
> superdict = addm(dict(), lambda self, d: myUtils.HasDrive(d),
> "hasdrive")
>
> and then I can call
>
> superdict.HasDrive('c')
>
> lambda makes it possible to add any random function because you can
> use it to set self as the first parameter. I've found several real
> uses for this already. My big question is, will something like this be
> possible in python 3000 if lambda really does go away? I've not heard
> much about lambda, reduce, etc. lately but I know Guido wanted them
> out of the language.
>
> Is there a better way to do this today than to use lambda? It seemed
> the simplest way to do this that I could find.
from win32com.client import Dispatch as CreateObject
class HDDs(list):
def __init__(self):
fso = CreateObject('Scripting.FileSystemObject')
for d in fso.Drives:
if d.DriveType == 2: # Fixed
list.append(self, d.DriveLetter)
if __name__ == "__main__":
drv_list = HDDs()
for d in drv_list:
print d
try:
# Found
print drv_list.index('P')
except ValueError:
# Not Found
print "P: Not Exists!"
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