Wikipedia:Reference desk/Archives/Computing/2015 February 6

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February 6

window-7

I like to install window 7 in my laptop. how can I do. If i install window 7 with the help of installing disc will it automatically remove existing window 8.1 ramrash — Preceding unsigned comment added by Ramrash (talk • contribs) 02:24, 6 February 2015 (UTC)

It should give you the option during the install process either to install Windows 7 in addition to Windows 8.1 or format the disk, which will erase everything including any files you have not backed up, then install Windows 7 on the now blank hard drive. As far as the installation process itself, simply insert the cd into your computer during boot-up and make sure your computer is set to boot to the CD before the hard drive. This process varies depending on your BIOS, so if you still need help setting that up, please let us know what BIOS you are running. RegistryKey^(RegEdit) 15:36, 6 February 2015 (UTC)

Not quite that simple, as there will probably not be any available drive space so you will need to resize the partitions. And Windows 8 Fast Start can cause issues with Windows 7, so it needs to be disabled. I found a guide for this that looks pretty good: [1]. --  Gadget850 ^talk 11:57, 7 February 2015 (UTC)

Three-letter ISO 639-2 language codes supported by iPhone?

I've got information that iPhone 6 supports the use of Swiss German with the three-letter ISO 639-2 code gsw. I failed to verify this in iBabble-on or anywhere else, but still I'm sure that it's correct. Two questions:

1. Is there a public list of ISO 639-2 codes already supported by iOS, or that will be supported in the near future?
2. Does iOS anyway use ISO 639-2 only for those languages without an ISO 639-1 two-letter code? Or might a 639-2 be used also for languages with an existing 639-1 code?

--KnightMove (talk) 10:05, 6 February 2015 (UTC)

Addendum: The explanation might well be this code from iBabble-on linked above:

"NEW in Xcode 6 and iOS 8: You can now specify any regional dialect you wish, AND include languages that Apple has not yet localized. Your users will have to select the language from the new Language and Region settings in the Settings.app. Note that the language will display only for iOS 8 users. For users running previous versions of iOS, the system will actually ignore the localization folder completely for regional dialects like pt-PT and for languages like Farsi that have no system-wide localizations. Those users will see your app's default language."

What exactly does "ANY" language mean? Any language with an ISO 639-2 code? Any language with any version of ISO 639 code? --KnightMove (talk) 11:00, 6 February 2015 (UTC)

Consult the Localization and Internationalization guide for iOS, which explains how it works in detail. ISO 639-1 and 639-2 forms are accepted (Appendix B for details). Nimur (talk) 14:59, 6 February 2015 (UTC)

How I delete a value from a list of lists in python?

Imagine I have this

• A =Variable that is a list
• B and C =Lists that are inside list A
• X and Y = values inside list B
• Z and W = Values inside list C

How do I remove as some example, the value the second value of list C (so, the value w)?
PS: I want to remove an item by poiting an index array and not the value the item has.
Tried to find using google, but it talk only about lists (tried to come with something out of the examples but nothing worked) and not about lists of lists. 201.78.203.109 (talk) 18:30, 6 February 2015 (UTC)

>>> B = ['X', 'Y']
>>> C = ['Z', 'W']
>>> A = [B, C]
>>> A
[['X', 'Y'], ['Z', 'W']]
>>> del A[1][1]
>>> A
[['X', 'Y'], ['Z']]
>>> C
['Z']

-- Mr.Z-man 19:03, 6 February 2015 (UTC)

Haven't studied Python at all, but a quick Google search turned up this: In Python, how do I delete the Nth list item from a list of lists (column delete)? Hope it helps! RegistryKey^(RegEdit) 19:10, 6 February 2015 (UTC)

A[1].pop(1) — There may be some subtle difference in side-effects from Z's version. —Tamfang (talk) 05:56, 7 February 2015 (UTC)

Thanks Z man. Anyway thats exacly what I was doing but the program was saying 'List Index out of bounds', so I guess its a problem on the code and not on the way i made the deletion procedure.201.78.203.109 (talk) 10:48, 9 February 2015 (UTC)

Two hints: Python, like many modern programming languages, starts indexing at 0, so valid indices for a list of n elements are 0,...,n-1. Secondly, you can use "assert" in Python to check assumptions your code makes, and to make it fail noisily if its in an unexpected state. This is particularly useful to verify parameters of a function, or invariants of an object. --Stephan Schulz (talk) 16:07, 7 February 2015 (UTC)

Thanks, anyway I already found the problem and fixed it. Actually I did more than that, after founding the problem, I actually cleaned the code in a way there is no need delete an item of an list that is inside another list. 201.78.203.109 (talk) 10:48, 9 February 2015 (UTC)

What would happen if you deleted system32 folder on a windows computer

I know that is where all the kernel windows processes are. What if you deleted it? What would actually happen? — Preceding unsigned comment added by Radioactivemutant (talk • contribs) 19:59, 6 February 2015 (UTC)

Try it and you have your answer. Dat's ta way to learn : ¬ ) --Aspro (talk) 20:48, 6 February 2015 (UTC)

Oh. Back up everything first!--Aspro (talk) 20:51, 6 February 2015 (UTC)

Here's a youtube video showing what happens in XP [2]. SemanticMantis (talk) 21:08, 6 February 2015 (UTC)

If you loaded (say) XP into a VM. You can mess about with it, to your hearts content and keep rolling back... so you can do it again and again and again. Try this, using a Linux Mint pen-drive with a VM (sacrilege I know but a lot of fun). --Aspro (talk) 22:44, 6 February 2015 (UTC)

Forgive me for being grumpy (!) but our OP is very mistaken! Processes are not the same as files - especially not on Windows! Hopefully we can correct this conceptual misunderstanding so they can develop a more full understanding of how this all works.

When you delete (or try to delete) system files, you remove them from the file system. Tongue twister though that is, it is conceptually very different from killing the processes that they represent. This is, for example, why it is possible on certain types of *nix-like systems to hot-swap the kernel - you can (in concept) replace the file on disk, re-load it into RAM, and then jump into it. In practice - a real operating system like Windows or Linux throws in a ton of extra "gotchas." Files may embody dynamic library data or page files. It is not easy to determine when the system will load that data from disk, or commit back to disk: it may not be possible to safely operate the system while simultaneously modifying these files. Systems like Windows therefore forbid the file manager from (easily) modifying these important files. Unless there is a reason to engineer this type of behavior and ensure that it is functional, the system may behave in "an unspecified fashion."

Whether the important files live in system32 or in any other location is moot; but the key thing to know is that the system software has expectations about what it can safely assume is on disk (or otherwise in persistent storage). If you (the user) intentionally violate these assumptions, the system will break. Because Windows is not free software, it is difficult for a hobbyist to study how these behaviors work with very much detail. However, there is a wide community of researchers who are interested in systems that can self-modify their system-software at runtime. For example, ksplice is linux technology that allows Linux to modify its own kernel at runtime. I even once worked on a system that could modify its own CPU architecture at runtime - it was fascinatingly complicated! So if you are interested in studying this kind of behavior, there are better environments than Windows. Windows is designed and sold as an operating system for ordinary application-users, so it's not great for system-level software experimentation of this sort. Nimur (talk) 00:43, 7 February 2015 (UTC)

Mistaken? That is why our OP asked the question! However, having said that, me thinks you gave a very good and informative reply.--Aspro (talk) 15:07, 7 February 2015 (UTC)