🌐 Mailman 3 April 2019 - Tutor - python.org

Scripting Calligra sheets with Python
by Jim Byrnes Jan. 31, 2022

Jan. 31, 2022

I am trying to script Calligra Sheets (formerly KSpread) with python. I have gotten some of the included example scripts to run so I know python scripting is running. I found the following snippet on their website: import KSpread sheet = KSpread.view().sheet() # swap text of B5 and C6 t1 = sheet.text("B5") t2 = sheet.text(6,3) sheet.setText("B5", t2) sheet.setText(6, 3, t1) # swap value of D7 and E8 v1 = sheet.value("D7") v2 = sheet.value(8,5) sheet.setValue("D7", v2) sheet.setValue(8, 5, v1) Error: 'str' object has no attribute 'text' File "file:///usr/share/kde4/apps/sheets/scripts/extensions/myswap.py", line 4, in <module> This error message appeared in a dialog box. I've taught myself some Python but I don't understand what is happening here. Shouldn't t1 be a sheet object? What would cause it to be a str instead? Thanks, Jim

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self.name is calling the __set__ method of another class
by Arup Rakshit May 2, 2019

May 2, 2019

Hi, In the following code, class attributes name and email is set to the instances of NonBlank. class NonBlank: def __init__(self, storage_name): self.storage_name = storage_name def __set__(self, instance, value): if not isinstance(value, str): raise TypeError("%r must be of type 'str'" % self.storage_name) elif len(value) == 0: raise ValueError("%r must not be empty" % self.storage_name) instance.__dict__[self.storage_name] = value class Customer: name = NonBlank('name') email = NonBlank('email') def __init__(self, name, email, fidelity=0): self.name = name self.email = email self.fidelity = fidelity def full_email(self): return '{0} <{1}>'.format(self.name, self.email) if __name__ == '__main__': cus = Customer('Arup', 99) Running this code throws an error: Traceback (most recent call last): File "/Users/aruprakshit/python_playground/pycon2017/decorators_and_descriptors_decoded/customer.py", line 25, in <module> cus = Customer('Arup', 99) File "/Users/aruprakshit/python_playground/pycon2017/decorators_and_descriptors_decoded/customer.py", line 18, in __init__ self.email = email File "/Users/aruprakshit/python_playground/pycon2017/decorators_and_descriptors_decoded/customer.py", line 7, in __set__ raise TypeError("%r must be of type 'str'" % self.storage_name) TypeError: 'email' must be of type 'str' Process terminated with an exit code of 1 Now I am not getting how the __set__() method from NonBlank is being called inside the __init__() method. Looks like some magic is going on under the hood. Can anyone please explain this how self.name and self.email assignment is called the __set__ from NonBlank? What is the name of this concept? Thanks, Arup Rakshit ar(a)zeit.io

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Fwd: Re: feedparser in python
by Alan Gauld April 30, 2019

April 30, 2019

Sharing with the list, comments later. Busy right now. -------- Forwarded Message -------- Subject: Re: [Tutor] feedparser in python Date: Tue, 30 Apr 2019 14:14:35 +0000 From: nathan tech <nathan-tech(a)hotmail.com> To: Alan Gauld <alan.gauld(a)yahoo.co.uk> Hi Alan, Thanks for your emails. I considered what you said, and came up with a couple of possibilities, listed below. Before that, I wanted to clarify what I meant when I said "not working." I kept meaning to do it, and kept forgetting. According to the docs: ?????? f=feedparser.parse(url) Will download a feed, parse it into xml, and return a dict of that feed, which it does. There are obviously some special things going on with tha,t because it allows, for instance, f.entries[0].title, rather than f["entries"][0]["title"]. Anyway. The docs then say that feedparser will have elements of etag and modified, which you can then pass in an update, like so: ?????? newfeed=feedparser.parse(url, etag=f.etag, modified=f.modified) To that end, it would check the headers, and if the feed was not updated, set newfeed.status to 304. Which is great, accept... My feeds never have a .etag or a .modified anywhere. Even f.get("etag") returns None. which while I could pass it that way, would mean the feed gets downloaded over and over and over again. In an example of an rss feed of size 10 MB, that's 240 MB a day, and by 3 days you're over a GIG. To that end, when I said not working, I meant, nothing I parsed in place of f.etag and or f.modified seemed to work in that it juts downloaded the entire feed agai Now, onto some solutions: I considered what you said and realised actually, logic says all we need to know is: is file on local hard drive older than file on web server, right? Which lead me briefly to, would os.path.getfilemtime work? Probably not, but I am curious if there are alternatives to thhat. In any case, finally I thought, what about f.entries This is a list of entries in an rss feed. Even without an update key, which they usually have: ?? date=f.entries[0].updated = "Fri, August 20th 2009" We could simply do: ?? if(downlaoded_first_entry==f.entries[0]): ???????? # feed is jup to date, so quit. This is where I got stuck. urllib2.urlopen() from my calculations, seems to download the file, then open it? Is that correct, or is that wrong? I wrote up this function below: ?????? import urllib2 ?????? import time ?????? url="https://www.bigfinish.com/podcasts.rss" ?????? start_time=time.time() ?????? j=urllib2.urlopen(url) ?????? j.close() # lets not be messy ?????? print time.time()-start_time That came out at 0.8 seconds. perhaps that is just network connectivity? but if we remember back to the tests run with the tim function, the difference in time there was around 1.1 seconds. The similarities were.. worrying is all. If urllib2.urlopen doesn't download the file, and merely opens a link up, as it were, then great. My theory here is to: open the web file, discard any data up to "<item>" until "</item>" is reached, save the data to a list. Covnert that list using an xml parser into a dictionary, and then compare either updated, title, or the whole thing. If one of them says, this isn't right, download the feed. If they match, the feed on local drive is up to date. To be fair, I could clean this up further, and simply have: until </title> or </updated> is reached save to a list, but that's a refinement for later. I'm looking forward to hear your thoughts on this. I picked up python myself over the course of a year, so am not quite used to having back and forth like these yet. Especially not with someone who knows what they're talking about. :) Thanks Nate On 30/04/2019 08:47, Alan Gauld via Tutor wrote: > On 30/04/2019 00:23, nathan tech wrote: > >> The results were as follows: >> >> ?????? tim( a url): 2.9 seconds >> >> ?????? tim(the downoaded file(: 1.8 seconds >> >> >> That tells me that roughly 1.1 seconds is network related, fair enough. > Or about 30% of the time. > Since the network element will increase as data > size increases as will the parse time it may be > a near linear relationship. Only more extensive > tests would tell. > >> entire thing again, they all say use ETAG and Modified, but my feeds >> never, have them. >> >> I've tried feeds from several sources, and none have them in the http >> header. > Have you looked at the headers to see what they do have? > >> To that end, that is why I mentioned in the previous email about .date, >> because that seemed the most likely, but even that failed. > Again you tell us that something failed. But don't say > how it failed. Do you mean that date did not exist? > Why did you think it would if you had already inspected > the headers? > > Can you share some actual code that you used to check > these fields? And sow us the actual headers you are > reading? > >> 1, download a feed to the computer. >> >> 2. Occasionally, check the website to see if the donloaded feed is out >> of date if it is, redownload it. > Seems a good plan. You just need to identify when changes occur. > > Even better would be if the sites provided a web API to access > the data programmatically, but of course few sites do that... > > >> I did think about using threading for this, for example: >> user sees downloaded feed data only, in the background, the program >> checks for updates on each feed, and the user may see them gradually >> start to update. >> >> This would work, in that execution would not fail at any time, but it >> seems... clunky, to me I suppose? And rather data jheavy for the end >> user, especially if, as you suggest, a feed is 10 MB in size. > Only data heavy if you download everything. If you only do the > headers and you only have a relatively few feeds its a good scheme. > > As an alternative is there anything in the feed body that identifies > its creation date? Could you change your parsing mechanism to > parse the data as it arrives and stop if the date/time has not > changed? That minimises the download data. > >> Furthering to that, how many threads is safe? > You have a lot of I/O going on so you could run quite a few threads > without blocking issues. How many feeds do you watch? Logic > would say have one thread per feed. > > But how real time does this really need to be? Would it be > terrible if updates were, say 1 minute late? If that's the case > a single threaded solution may be fine. (and much simpler) > I'd certainly focus on a single threaded solution initially. Get it > working first then think about performance tuning. > >

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feedparser in python
by nathan tech April 30, 2019

April 30, 2019

Hello everyone, Most recently, I have started work using feedparser. I noticed, almost straight away, it's a bit slow. For instance: url="http://feeds.bbci.co.uk/news/rss.xml" f1=feedparser.parse(url) On some feeds, this can take a few seconds, on the talk python to me feed, it takes almost 10! This, obviously, is not ideal when running a program which checks for updates every once in a while. Talk about slooooow! I tried using etag, and modified, but none of the feeds seem to ever have them! Similarly, this doesn't seem to work: f2=feedparser.parse(url, f.headers["date"]) What am I doing wrong? Any help appreciated. A greatly frustrated Nate

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What does 'Bind Return Key' do?
by Matthew Polack April 29, 2019

April 29, 2019

Hi, We're learning Python with PySimpleGUi and have used this example program... https://github.com/PySimpleGUI/PySimpleGUI/blob/master/ProgrammingClassExam… There is a mystery command that says: [sg.ReadButton('Submit', bind_return_key = False)]] If I change this 'Bind_Return_Key' value from False to True...or in fact delete it entirely, it appears to make do difference whatsoever to the functioning of the program that I can see... Could someone explain what the purpose of this could be? I'm guessing it has to have a reason to be there! Thanks! -- **Disclaimer: *Whilst every attempt has been made to ensure that material contained in this email is free from computer viruses or other defects, the attached files are provided, and may only be used, on the basis that the user assumes all responsibility for use of the material transmitted. This email is intended only for the use of the individual or entity named above and may contain information that is confidential and privileged. If you are not the intended recipient, please note that any dissemination, distribution or copying of this email is strictly prohibited. If you have received this email in error, please notify us immediately by return email or telephone +61 3 5382 2529** and destroy the original message.*

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Help request ERROR installing beautifulsoup
by Dr. Luca T April 29, 2019

April 29, 2019

Hi, i'm new in python, i tried to install beautifulsoup but i had back this error: ERROR: Complete output from command python setup.py egg_info: ERROR: Traceback (most recent call last): File "<string>", line 1, in <module> File "C:\Users\Luca\AppData\Local\Temp\pip-install-u6zd808q\beautifulsoup\setup.py", line 22 print "Unit tests have failed!" ^ SyntaxError: Missing parentheses in call to 'print'. Did you mean print("Unit tests have failed!")? ---------------------------------------- ERROR: Command "python setup.py egg_info" failed with error code 1 in C:\Users\Luca\AppData\Local\Temp\pip-install-u6zd808q\beautifulsoup\ I use windows 10, python 3.7.3 and a minipc with 32-bit technology inside, can you help me telling me where i'm wrong please? 🙂 Thanks. Luca Tartufari

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When you think to setup the __class__ of a module object to a subclass of ModuleType
by Arup Rakshit April 28, 2019

April 28, 2019

In the simple code like what are the advantages we get from? Is this so that we can implement more special methods than just __getattr__ and __dir__ in the module level? import sys from types import ModuleType class VerboseModule(ModuleType): def __repr__(self): return f'Verbose {self.__name__}' def __setattr__(self, attr, value): print(f'Setting {attr}...') super().__setattr__(attr, value) sys.modules[__name__].__class__ = VerboseModule I can see a use of its when I play with the module as. Am I thinking it right, or there are other reasons of this setup? import fine_grained_module fine_grained_module.foo = "foo” # Setting foo… repr(fine_grained_module) # 'Verbose fine_grained_module' Thanks, Arup Rakshit ar(a)zeit.io

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Use case of attaching list of strings as spec to the Mock.mock_add_spec() method?
by Arup Rakshit April 28, 2019

April 28, 2019

Code: from unittest.mock import Mock class C: def get_val(self): print(1) mock = Mock() mock.mock_add_spec(C()) mock.get_val.side_effect = C().get_val print(isinstance(mock, C)) True mock.get_val() 1 In the above code, if I replace `mock.get_val.side_effect = C().get_val` with `mock.get_val.return_value = 1` the code still works same. from unittest.mock import Mock class C: def get_val(self): print(1) mock = Mock() mock.mock_add_spec(C()) mock.get_val.return_value = 1 print(isinstance(mock, C)) True mock.get_val() 1 So question is that: Are there any difference using side_effect and return_value while configuring a return value of a method? From doc of [mock_add_spec()](https://docs.python.org/3/library/unittest.mock.html#unitt… it says: > Add a spec to a mock. spec can either be an object or a list of strings. What kind of string it refers here? any random valid strings? Why would some one try to mock a string objects instead of just using that string object itself? How does this part work while attaching a spec to the Mock? I understand the object spec part, not just the list of strings use case. So if anyone can explain this, I will be very helpful. Thanks, Arup Rakshit ar(a)zeit.io

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urlGET information
by Nathan D'Elboux April 28, 2019

April 28, 2019

Hi all, I am pulling apart a python script called Maltran from github and just looking at the modules its importing. the modules in use and that i can find plenty of info on are. import requests. import sys import re import time import urlGET # No information on urlGET as of yet https://pypi.org/project/urlget/ this is a learning exercise for me so how do more experienced python coders approach modules like this, when you encounter a module that has sparse documentation how do you learn more about the functionality of said module? unpack it and just read the source? or is there like a linux man page equivalent within the wheel that would provide more context? Thanks Nathan

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module import from a packager works inconsistent between REPL and command line
by Arup Rakshit April 26, 2019

April 26, 2019

I have a small app like this: pizza-shop$ tree . . └── pizzapy ├── __init__.py ├── menu.py └── pizza.py 1 directory, 3 files # menu.py from typing import List from pizza import Pizza MENU: List[Pizza] = [ Pizza('Margherita', 30, 10.0), Pizza('Carbonara', 45, 14.99), Pizza('Marinara', 35, 16.99), ] if __name__ == '__main__': print(MENU) # pizza.py import math class Pizza: name: str = '' size: int = 0 price: float = 0 def __init__(self, name: str, size: int, price: float) -> None: self.name = name self.size = size self.price = price def area(self) -> float: return math.pi * math.pow(self.size / 2, 2) def awesomeness(self) -> int: if self.name == 'Carbonara': return 9000 return self.size // int(self.price) * 100 print('pizza.py module name is %s' % __name__) if __name__ == '__main__': print('Carbonara is the most awesome pizza.') Now when I call the menu.py from command like it works as expected. pizza-shop$ python3 pizzapy/menu.py pizza.py module name is pizza [<pizza.Pizza object at 0x1035dbeb8>, <pizza.Pizza object at 0x1035fb2b0>, <pizza.Pizza object at 0x1036b6c50>] But it fails in REPL: pizza-shop$ python3 Python 3.7.3 (default, Mar 27 2019, 09:23:15) [Clang 10.0.1 (clang-1001.0.46.3)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> from pizzapy import menu Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/Users/aruprakshit/python_playground/pizza-shop/pizzapy/menu.py", line 2, in <module> from pizza import Pizza ModuleNotFoundError: No module named 'pizza' >>> What is the reason of this inconsistency ? Thanks, Arup Rakshit ar(a)zeit.io

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