Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #89552
| From | Grant Edwards <invalid@invalid.invalid> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Not possible to hide local variables |
| Date | 2015-04-29 14:16 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <mhqp33$dpj$2@reader1.panix.com> (permalink) |
| References | <874mo0zoz2.fsf@Equus.decebal.nl> |
On 2015-04-28, Cecil Westerhof <Cecil@decebal.nl> wrote:
> If I remember correctly you can not hide variables of a class or make
> them read-only?
>
> I want to rewrite my moving average to python. The init is:
> def __init__(self, length):
> if type(length) != int:
> raise ParameterError, 'Parameter has to be an int'
> if n < 0:
> raise ValueError, 'Parameter should be greater or equal 2'
> self.length = length
> self.old_values = []
> self.current_total = 0
>
> But when someone changes length, old_values, or current_total that
> would wreck havoc with my class instance. What is the best way to
> handle this?
It's like the punchline to the old doctor joke: if it hurts when you
do that, then don't _do_ that:
def __init__(self, length):
if type(length) != int:
raise ParameterError, 'Parameter has to be an int'
if n < 0:
raise ValueError, 'Parameter should be greater or equal 2'
self._length = length
self._old_values = []
self._current_total = 0
The convention is that properties that start with underscores are
private. They're not hidden, but if people touch them and it breaks
something, it's their fault. Whether you go all Torvalds on their ass
for doing so is left as an exercise for the reader.
--
Grant Edwards grant.b.edwards Yow! If Robert Di Niro
at assassinates Walter Slezak,
gmail.com will Jodie Foster marry
Bonzo??
Back to comp.lang.python | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Not possible to hide local variables Cecil Westerhof <Cecil@decebal.nl> - 2015-04-28 09:33 +0200
Re: Not possible to hide local variables Ethan Furman <ethan@stoneleaf.us> - 2015-04-28 00:56 -0700
Re: Not possible to hide local variables Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 08:16 +0200
Re: Not possible to hide local variables Michael Torrie <torriem@gmail.com> - 2015-04-29 21:10 -0600
Re: Not possible to hide local variables Chris Angelico <rosuav@gmail.com> - 2015-04-28 18:06 +1000
Re: Not possible to hide local variables Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 08:25 +0200
Re: Not possible to hide local variables Chris Angelico <rosuav@gmail.com> - 2015-04-29 17:36 +1000
Re: Not possible to hide local variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-28 18:37 +1000
Re: Not possible to hide local variables Chris Angelico <rosuav@gmail.com> - 2015-04-28 18:44 +1000
Re: Not possible to hide local variables Marko Rauhamaa <marko@pacujo.net> - 2015-04-28 12:20 +0300
Re: Not possible to hide local variables Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 08:32 +0200
Re: Not possible to hide local variables Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-04-30 14:05 +1000
Re: Not possible to hide local variables Marko Rauhamaa <marko@pacujo.net> - 2015-04-30 08:10 +0300
Re: Not possible to hide local variables Chris Angelico <rosuav@gmail.com> - 2015-04-30 16:01 +1000
Re: Not possible to hide local variables Cecil Westerhof <Cecil@decebal.nl> - 2015-04-29 08:14 +0200
Re: Not possible to hide local variables Grant Edwards <invalid@invalid.invalid> - 2015-04-29 14:16 +0000
Re: Not possible to hide local variables Dave Angel <davea@davea.name> - 2015-04-29 22:31 -0400
Re: Not possible to hide local variables Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2015-04-30 08:53 -0400
Re: Not possible to hide local variables Cecil Westerhof <Cecil@decebal.nl> - 2015-04-30 16:50 +0200
csiph-web