🌐 Mailman 3 February 2020 - Python-list - python.org

Re: encapsulating a global variable (BlindAnagram)
by Christman, Roger Graydon Feb. 25, 2020

Feb. 25, 2020

> On Tue, 25 Feb 2020 3:06 PM BlindAnagram <blindanagram(a)nowhere.com> wrote: > My interest in this stems from wanting to keep the dictionary only > available to the function that uses it and also a worry about being > called from threaded code. It seems like the simplest solution for this is to make a completely new file (module) containing nothing but the dictionary and this one function that uses it. Then you can import the function from the module wherever it is called without importing the dictionary. The thing I find curious is that apparently no other function is allowed to create or populate the dictionary in the first place. Is it practical to have the entire dictionary statically defined? Roger Christman Pennsylvania State University

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Re: encapsulating a global variable
by BlindAnagram Feb. 25, 2020

Feb. 25, 2020

On 25/02/2020 16:36, Rhodri James wrote: > On 25/02/2020 15:20, BlindAnagram wrote: >>> class GetIt: >>> seen = dict() >>> >>> def __call__(self, piece): >>> return GetIt.seen[piece] >>> >>> get_it = GetIt() >>> >>> but then you have a global class instance hanging around, which is not >>> actually any better than a global dictionary. >> This doesn't work for me since get_it(piece) returns the error: >> >> builtins.TypeError: get_it() takes no arguments > > It works for me (pace sticking something in GetIt.seen to avoid getting > a KeyError). You aren't muddling up the class name and instance name > are you? Apologies, I misunderstoof your proposal - it woks fine now I have understood it Brian

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Re: encapsulating a global variable
by BlindAnagram Feb. 25, 2020

Feb. 25, 2020

On 25/02/2020 14:14, Rhodri James wrote: > On 25/02/2020 12:38, BlindAnagram wrote: >> I would appreciate advice on whether it is possible to avoid the use of >> a global variable used in a function by encapsulating it in a class >> without maaking any changes to the call interface (which I cannot >> change). >> >> I have: >> >> ---------------- >> seen = dict() >> >> def get_it(piece): >> ... >> return seen[piece] >> ---------------- >> >> and I am wondering if it is possible to use a class something like >> >> ---------------- >> class get_it(object): >> >> seen = dict() >> >> def __call__(piece): >> return seen[piece] >> ---------------- >> >> to avoid the global variable. > > I wouldn't. Calling the class name creates an instance of the class, so > won't actually do what you want. You could rewrite the class and create > an instance to call instead: > > class GetIt: > seen = dict() > > def __call__(self, piece): > return GetIt.seen[piece] > > get_it = GetIt() > > but then you have a global class instance hanging around, which is not > actually any better than a global dictionary. This doesn't work for me since get_it(piece) returns the error: builtins.TypeError: get_it() takes no arguments Brian

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time.localtime add a parameter for timezone
by qbit Feb. 25, 2020

Feb. 25, 2020

How about adding a time zone parameter to time.localtime? A offset just like the form: ± hh[:mm[:ss]].

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Re: encapsulating a global variable
by BlindAnagram Feb. 25, 2020

Feb. 25, 2020

On 25/02/2020 12:56, Chris Angelico wrote: > On Tue, Feb 25, 2020 at 11:41 PM BlindAnagram <blindanagram(a)nowhere.com> wrote: >> >> I would appreciate advice on whether it is possible to avoid the use of >> a global variable used in a function by encapsulating it in a class >> without maaking any changes to the call interface (which I cannot change). > > Why bother? If you aren't changing where the function's called, then > its state is effectively global anyway, so what's the point of the > class? It's a good question! The main reason is that I would like to know if it is possible as I then have a choice. The choice might not be there. Brian

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Re: encapsulating a global variable
by BlindAnagram Feb. 25, 2020

Feb. 25, 2020

On 25/02/2020 12:50, Musbur wrote: > > Am 25.02.2020 13:38 schrieb BlindAnagram: >> and I am wondering if it is possible to use a class something like >> >> class get_it(object): >> >> seen = dict() >> >> def __call__(piece): >> return seen[piece] > > What happened when you tried it? The nearest I got was: ------------------------- class orientate(object): seen = defaultdict() @classmethod def do(self, piece, two_sided=False): ------------------------ which works but requires a change to the function call interface from orientate(piece) to orientate.do(piece). I was hoping that repalcing the above with: ------------------------- class orientate(object): seen = defaultdict() @classmethod def __call__(self, piece, two_sided=False): ------------------------ would eliminate the need for the 'do' but this gives the error: builtins.TypeError: orientate() takes no arguments Brian

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Re: encapsulating a global variable
by Musbur Feb. 25, 2020

Feb. 25, 2020

Am 25.02.2020 13:38 schrieb BlindAnagram: > and I am wondering if it is possible to use a class something like > > class get_it(object): > > seen = dict() > > def __call__(piece): > return seen[piece] What happened when you tried it?

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How to get a place's longitude and latitude?
by Souvik Dutta Feb. 24, 2020

Feb. 24, 2020

Hi guys I want to make a program that kinda sends an sos message with the measures of longitude and latitude (which is super inconvenient) to someone. How can I do that I mean how can I get the longitude and latitude? Any help would be appreciated.

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Re: How to get a place's longitude and latitude?
by Abdur-Rahmaan Janhangeer Feb. 24, 2020

Feb. 24, 2020

Ever heard of QPython? It has a sl4a Api http://edu.qpython.org/qsl4a-develop/index.html?form=web You can pull in GPS coordinates! On Mon, 24 Feb 2020, 20:07 Souvik Dutta, <souvik.viksou(a)gmail.com> wrote: > Yes. > > On Mon, 24 Feb, 2020, 9:36 pm Abdur-Rahmaan Janhangeer, < > arj.python(a)gmail.com> wrote: > >> On phone? >> >> On Mon, 24 Feb 2020, 20:02 Souvik Dutta, <souvik.viksou(a)gmail.com> wrote: >> >>> Hi guys I want to make a program that kinda sends an sos message with the >>> measures of longitude and latitude (which is super inconvenient) to >>> someone. How can I do that I mean how can I get the longitude and >>> latitude? >>> Any help would be appreciated. >>> -- >>> https://mail.python.org/mailman/listinfo/python-list >>> >>

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Re: Help with oop
by DL Neil Feb. 23, 2020

Feb. 23, 2020

On 24/02/20 10:45 AM, S Y wrote: > """ The class Baggage will track inventory items added to or removed > from it. Inventory items will be represented by > inventory item objects created using the ‘InventoryItem’ class. When an > attempt is made to add an inventory > item to a Baggage object, the number of items in the Baggage object is > compared with maximum capacity and > allowable items. If space is left and the item is allowed, the item is > added, otherwise, the class returns a response indicating failure with a > short reason why""" > class Baggage: > #Constructor - sets initial values for all object attributes. > def __init__(self,capacity, inventory= [],allow_items=()): > self.inventory = [] > self.capacity = 5 > self.allow_items = ( ... > #Adds an item object to the Baggage object after checking that the mx > capacity has not been reached (i.e. 5 items) > def add_item(self, item_object): > if len(self.inventory) <= self.capacity: > self.inventory.append(item_object) > return True > else: > print("Reached max capacity") > return False > <python-list-bounces+saliyusufm=outlook.com(a)python.org> on behalf of DL > Neil via Python-list <python-list(a)python.org> > *Sent:* Sunday, February 23, 2020 4:41:54 PM > *To:* python-list(a)python.org <python-list(a)python.org> > *Subject:* Re: Help with oop > On 22/02/20 10:45 PM, S Y wrote: >> How can I use remove,add and verify methods in class oop. Which has tuple with allowed values inside class. Like two classes cart and inventory > > Please show the code you have so-far. > What are you removing, adding, and verifying? > Are you aware of the Python-Tutor Discussion List? Given that the data-structure is a list, perhaps list.remove()? What is the relevance of Baggage.allow_items()? Sorry to be nagging you but perhaps take a look at how Discussion Lists work: - top/bottom posting, ie not answer then question, - replying to list (not individual) so that others may also benefit, - formatting and readability (cf 'Microsoft makes it look nice because they know better than you') WebRef: 5. Data Structures¶ https://docs.python.org/3/tutorial/datastructures.html -- Regards =dn

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