Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail
From: Prince Udoka <princeudo52@gmail.com>
Newsgroups: comp.lang.python
Subject: Re: Need help on a project To :"Create a class called BankAccount with the following parameters "
Date: Mon, 28 Dec 2015 23:35:15 +0100
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Xref: csiph.com comp.lang.python:100940

thanks everyone, though it was very tough, but i thank GOD

On Mon, Dec 28, 2015 at 11:29 PM, Cameron Simpson <cs@zip.com.au> wrote:

> On 28Dec2015 01:34, Prince Udoka <princeudo52@gmail.com> wrote:
>
>> bu i have come up with a solution, that will work but encounter a problem
>> in the set, giving set not manipulated correctly:
>>
>> def manipulate_data(kind, data):
>>    if kind == 'list':
>>        return list(data)[::-1]
>>    elif kind == 'set':
>>        return set(data)
>>    elif kind == 'dictionary':
>>        return dict.keys(data)
>> manipulate_data("list", range(1,6))
>> manipulate_data("set", {"a", "b", "c", "d", "e", "ANDELA", "TIA",
>> "AFRICA"})
>> manipulate_data("dictionary", {"apples": 23, "oranges": 15, "mangoes": 3,
>> "grapes": 45})
>>
>> the thing now is the function to use in adding "ANDELA", "TIA", "AFRICA"
>> pls 4give my use of language
>>
>
> You are very close. Let me remind you of the original task text:
>
>  add items `"ANDELA"`, `"TIA"` and `"AFRICA"` to the set and return the
> resulting set
>
> Your previous attempt (with hardwired values inside the function) actually
> had code to do it.
>
> While you have pulled out all the hardwired values from the function
> (good) and put them in the external calls, note that the task explicitly
> says "add items `"ANDELA"`, `"TIA"` and `"AFRICA"` to the set". So _those_
> values _are_ supposed to be hardwired inside the function - they are a
> fixed part of the task. So move them back in, as in your previous attempt.
>
> There is some ambiguity in that part of the question: should you return a
> _new_ set consistint of the original set plus the three new values, or
> simply add the three values to the original set? Your prior code modified
> the original set, which may fit the task specification.
>
> However, it is a common design objective that functions do not,
> _normally_, modify their arguments. So, consider this code:
>
>  set1 = {"a", "b", "c", "d", "e"}
>  set2 = manipulate_data("set", set1)
>
> After running this, set2 should look like this:
>
>  {"a", "b", "c", "d", "e", "ANDELA", "TIA", "AFRICA"}
>
> (in some order -- sets are not ordered). However, what about set1? In your
> current code, set1 is modified, so it will be the same. But you can imagine
> that it would be more useful for the caller if set1 were unchanged.
>
> In python, the convention is usually that if a function returns the new
> value then it should not modify the original. So you should probably
> construct a copy of the original set and modify that:
>
>  data = set(data)
>  ... add the new values ...
>  return data
>
> Cheers,
> Cameron Simpson <cs@zip.com.au>
>