Mailman 3 December 2021 - docs

A suggestion for improving the documentation of chapter 10.9. Data Compression
by Guy Goldner May 22, 2024

May 22, 2024

Hello dear Python gods :) I'm new at Python and was going over the documentation . This useful paragraph : https://docs.python.org/3.7/tutorial/stdlib.html#data-compression provides info for compressing text but IMHO some important additional info is needed, without which I expect nearly all users would get stuck just as I have. Moreover, while looking for a solution I noticed a lot of articles with outdated examples which no longer work - this confused me even more to the point I started suspecting something was amiss on my end... Anyhow, adding this info would do the trick : zlib works only with bytes and in Python 3.x strings are no longer bytes. Example : *>>> zlib.compress('this is a sample string which does not work in zlib because it requires bytes and not unicode')Traceback (most recent call last): File "<stdin>", line 1, in <module>TypeError: a bytes-like object is required, not 'str'>>>* Luckily Python has a very simple solution for this : encode to utf-8, compress, decode back to unicode like so : *>>> text = 'this is a sample string which does not work in zlib because it requires bytes and not unicode with chars like this »שלום '>>> encoded = text.encode()>>> text = 'this is a sample with unicode chars »שלום '>>> encoded = text.encode()>>> compressed = zlib.compress(encoded)>>> decompressed = zlib.decompress(compressed)>>> decoded = decompressed.decode()>>> len(text),len(encoded),len(compressed) #notice that compression of short strings can be larger than the original(42, 47, 54)>>> print(text,'\n',encoded,'\n',compressed)this is a sample with unicode chars »שלום b'this is a sample with unicode chars \xc2\xbb\xd7\xa9\xd7\x9c\xd7\x95\xd7\x9d ' b'x\x9c+\xc9\xc8,V\x00\xa2D\x85\xe2\xc4\xdc\x82\x9cT\x85\xf2\xcc\x92\x0c\x85\xd2\xbc\xcc\xe4\xfc\x94T\x85\xe4\x8c\xc4\xa2b\x85C\xbb\xaf\xaf\xbc>\xe7\xfa\xd4\xebs\x15\x00\xb2K\x14|'>>> text == decodedTrue* Thank you ! You are doing a great thing ! B.R., Guy Goldner

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SMTPHandler secure argument without credentials
by William Edwards Sept. 15, 2022

Sept. 15, 2022

logging.handlers.SMTPHandler only uses the 'secure' argument when credentials are specified. https://docs.python.org/3/library/logging.handlers.html#logging.handlers.SM… says: "To specify the use of a secure protocol (TLS), pass in a tuple to the secure argument. This will only be used when authentication credentials are supplied." The docstring confirms this, but I can't find an explanation of the intent behind this behaviour. Perhaps it would be a good idea to describe this as well.

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Bug in Python.
by Prakash Mudholkar Feb. 7, 2022

Feb. 7, 2022

Hello - I wish to bring to your kind notice a bug in Python. Given any matrix X. While trying to compute the CoVariance matrix of that matrix X, Python does NOT compute the CoVarianceof the given matrix X. Instead, Python comptes the CoVariance of the Transpose of the given matrix X. This appears to be a bug in Python. Please refer to the below website for a given matrix and what the result should be after the computation of it's CoVariance. And I have provided a screenshot of what Python is returning. https://www.itl.nist.gov/div898/handbook/pmc/section5/pmc541.htm Please let me know if you have any questions. Regards, Prakash

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https://docs.python.org/es/3/library/
by t132654 Dec. 31, 2021

Dec. 31, 2021

Good day. I would like to make a suggestion for improvement on how the documentation page works. The left panel where the content tree is displayed should move independently of the right panel where the selected content is displayed, so that selecting new content in the left panel does not require scrolling to the top of the page. Thanks for your attention. Happy holidays and best regards. Ramón.

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Request a missing feature
by Avichal Kumar Dec. 31, 2021

Dec. 31, 2021

Hello sir I am a python learning student, I found some missing feature in matplotlib.pyplot I'm using python in vscode, and i wanted to run two code at same time, when I'm trying to do then firstly I need to close that figure which is printed the print next, but i can't run two matplotlib code at same time, but i wanted to see both figure at same time, this is the missing feature that i found, I can send you video also

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documentation error?
by Sean Carter Dec. 31, 2021

Dec. 31, 2021

In section 9.3.5. Class and Instance Variables, it makes a distinction between class and instance variables that doesn't look completely right. It looks to me like what's going on is that class variables are bound when the interpreter gets to that class, kind of like default parameters to functions, and then a copy of the class variable is created when the class is instantiated. BUT, in the case of a list, it's a shallow copy, so you end up in a situation where every instance is aliased to the same place in memory, which gives the *illusion* of a hard distinction between class and instance variables. For example, try this: class Dog: kind = 'canine' # class variable shared by all instances def __init__(self, name): self.name = name # instance variable unique to each instance d = Dog('Fido') e = Dog('Buddy') d.kind # shared by all dogs print(d.kind, e.kind, d.name, e.name) d.kind = 'felis sylvestris' print(d.kind, e.kind, d.name, e.name) The output will be: canine canine Fido Buddy felis sylvestris canine Fido Buddy Which would not be the case if those were truly "class variables" Sean

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python bug
by Levente Asztalos Dec. 27, 2021

Dec. 27, 2021

So, I've been trying to make a memory game.. kind of.. And I noticed a bug and it was buggy every code where I was using this The bug is, when I Try to print a random generated number with IDLE, nothing wrong but when I open it as a regular app, it do not working, sending pictures screen1 is the code screen2 is the code running in IDLE perfectly screen3 is the buggy stuff

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epub version - performance problems
by Mirek Kaim Dec. 20, 2021

Dec. 20, 2021

Epub version of the docs absolutely chokes PocketBook Touch Lux 5. Not sure if splitting it up into separate parts like it was done with pdf files would help, or if it’s something else, but it seems like a step in the right direction. Ebook readers usually have limited specs - PocketBook runs some custom Linux distro, so despite dual core cpu and 512MB of ram it works nicely overall. Some readers with similar specs are running android, and that ends up being way slower. Throw an ebook with thousands of unoptimized pages on such thing and it’ll just hang. Best regards, Mirek

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Basic But Very Major Bug
by Yatharth Saini 9A Dec. 18, 2021

Dec. 18, 2021

hi, I am a beginner, but still you must see this prob. See this code: If i will Put the value of X = 1, it will show Not Valid! , At this moment python should show an error that , how can be the variable X , be int and float at the same time , But still it shows Not Valid! I think it needs to be fixed to make python more intelligent language. if isinstance(x, int) and isinstance(x, float) and x=='1': print("Valid type!") else: print("Not valid!")

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Bug in https://docs.python.org/3.10/library/string.html
by Richard Hyde Dec. 15, 2021

Dec. 15, 2021

One of the examples of string formatting doesn't work. This applies to prior versions of Python as well. The last set of the examples headed: 'Nesting arguments and more complex examples:' starts with the following code: >>> for align, text in zip('<^>', ['left', 'center', 'right']):... '{0:{fill}{align}16}'.format(text, fill=align, align=align)... This omits print()The correct code would be: >>> for align, text in zip('<^>', ['left', 'center', 'right']):... print('{0:{fill}{align}16}'.format(text, fill=align, align=align))... Best wishes Richard Hyde

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