List append help

[Bill]

I am trying to do an exercise in an online tutorial that but the tutorial
does not list the solution. Could someone please tell me why the "hireCrew"
method in the following code leaves me with a list that contains "None"? Be
nice, this is my first go at this, thanks!

class Organization:
def __init__(self, argName, argLeader, argCrew):
self.myName = argName
self.myLeader = argLeader
self.myCrew = argCrew

def getName(self):
return self.myName

def setLeader(self, argLeader):
self.myLeader = argLeader

def getLeader(self) :
return self.myLeader

def getCrew(self):
return self.myCrew

def hireCrew(self, argHire):
self.myCrew = self.myCrew.app end(argHire)
return self.myCrew

x = Organization("M yOrg", "JB", ["TL", "BK"])
print x.getName(), x.getLeader(), x.getCrew()
x.hireCrew("PD" )
print x.getName(), x.getLeader(), x.getCrew()

[Miki Tebeka]

Re: List append help

Hello Bill,
[color=blue]
> Could someone please tell me why the "hireCrew"
> method in the following code leaves me with a list that contains "None"?
> ...
> self.myCrew = self.myCrew.app end(argHire)[/color]
The return value of list.append is None. However it does add the item to
the list. Try:
self.myCrew.app end(argHire)

On a side note, I find this `arg' prefix for an argument irritating :-)

HTH.
Miki

[Bill]

Re: List append help

Thank you, This was really bugging me. To help me understand, do you know
why the return value was None even though it was added to the list? Also, I
don't like having to type "arg" on every other line neither, so I won't:-)

Miki Tebeka <miki.tebeka@zo ran.com> wrote:[color=blue]
>
>Hello Bill,
>[color=green]
>> Could someone please tell me why the "hireCrew"
>> method in the following code leaves me with a list that contains "None"?
> > ...
> > self.myCrew = self.myCrew.app end(argHire)[/color]
>The return value of list.append is None. However it does add the item to
>the list. Try:
>self.myCrew.ap pend(argHire)
>
>On a side note, I find this `arg' prefix for an argument irritating :-)
>
>HTH.
>Miki[/color]

[David Lewis]

Re: List append help

In article <1058329gsgeq85 f@corp.supernew s.com>, Bill wrote:
[color=blue]
> Thank you, This was really bugging me. To help me understand, do you know
> why the return value was None even though it was added to the list?[/color]

It¹s a philosophical decision made throughout Python. When an operation
is destructive (i.e. it changes the object on which it operates rather
than returning a new, changed, object), it returns None to emphasize
the point.

Best,
David

[Guest]

Re: List append help

Thank you!

David Lewis <DavidMLewis.NO @SPAM.mac.com> wrote:[color=blue]
>
>In article <1058329gsgeq85 f@corp.supernew s.com>, Bill wrote:
>[color=green]
>> Thank you, This was really bugging me. To help me understand, do you know
>> why the return value was None even though it was added to the list?[/color]
>
>It¹s a philosophical decision made throughout Python. When an operation
>is destructive (i.e. it changes the object on which it operates rather
>than returning a new, changed, object), it returns None to emphasize
>the point.
>
>Best,
> David[/color]