Mailman 3 June 2023 - docs

A suggestion for improving the documentation of chapter 10.9. Data Compression
by Guy Goldner 22 May '24

22 May '24

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 Moreover, while looking for a solution I noticed a lot of articles with outdated examples which no longer work - this confused me even more to the point I started suspecting something was amiss on my end...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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Potential typo in Profiler docs?
by 2dfkit 09 Nov '23

09 Nov '23

In the[profiler docs](https://docs.python.org/3/library/profile.html), under the first profiler output example, it says > ... The next line:Ordered by: cumulative time, indicates that the text string in the far right column was used to sort the output. This doesn't appear to make sense, and indeed the example output is sorted by the "cumtime" column, and not by the text string column at the far right. Am I misreading this or is this a typo? Thanks! PS. Sorry I didn't raise a ticket, I'm new and shy about posting in public forums

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bug reports for the documentation (mainly the tutorial)
by Stephan Stiller 30 Oct '23

30 Oct '23

Dear list, I recently read through the entire Python tutorial and FAQ (v3.11.2) and took notes on things that I believe to be errata. Here is my list: 1. https://docs.python.org/3/tutorial/controlflow.html I think it would be better if there were a pastable space after "144 233 377 610 987 1597" (and in some other places in the tutorial). My guess is that the present formatting has to do with the way these pages are generated. 2. https://docs.python.org/3/library/stdtypes.html#dict.get I think "get(key[, default=None])" would be better than "change get(key[, default]). 3. https://docs.python.org/3/library/stdtypes.html#mapping-types-dict It seems that "sorted(d)" is missing from the documentation, at least on this page. The output (sorted list of all keys) is not predictable for a beginner, so it might be better to be explicit. 4. https://docs.python.org/3/tutorial/modules.html About the instruction for loading "fibo" ("Now enter the Python interpreter and import this module with the following command:"): Many beginners will be using IDLE. If on Windows, one needs to import the file like this: import sys sys.path.append(r'C:\path_to_directory_with_fibo') import fibo Adding a remark like this will help the reader. 5. https://docs.python.org/3/tutorial/inputoutput.html The '{:-9} YES votes {:2.2%}'.format(yes_votes, percentage) example will slow a careful first-time reader down. I suggest explaining the two expressions in curly braces briefly on the side, in one sentence each. 6. https://docs.python.org/3/tutorial/inputoutput.html#old-string-formatting I would replace the second sentence by something like the following For the expression "format % values", "%" conversion specifications in "format" are replaced with zero or more elements of "values". or something similar adapted from here: https://docs.python.org/3/library/stdtypes.html#old-string-formatting 7. https://docs.python.org/3/library/functions.html#open I strongly suggest replacing "buffering=- 1" by "buffering= -1". I suspect this might be a systematic bug generated by a formatter. Similarly, here https://docs.python.org/3/library/stdtypes.html#str.split I would replace "str.split(sep=None, maxsplit=- 1)" by "str.split(sep=None, maxsplit= -1)". In both cases, deleting the space entirely is an alternative option. 8. https://docs.python.org/3/tutorial/errors.html#exceptions If I understand correctly, I believe it will be clearer if "and execution stops with a message as shown above" is shortened to simply "and execution stops". 9. https://docs.python.org/3/faq/extending.html#how-do-i-extract-c-values-from… "PyListSize()" should probably read "PyList_Size()". General comments: I believe that a HOWTO on "object-oriented programming" best practices in Python would be useful. Perhaps there is one, but I couldn't find it. Best regards, Stephan Stiller

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https://docs.python.org/3/library/timeit.html
by Goldberg, Arthur P 30 Oct '23

30 Oct '23

Hello In this section This is a convenience function that calls timeit()<https://docs.python.org/3/library/timeit.html#timeit.Timer.timeit> repeatedly so that the total time >= 0.2 second, returning the eventual (number of loops, time taken for that number of loops). It calls timeit()<https://docs.python.org/3/library/timeit.html#timeit.Timer.timeit> with increasing numbers from the sequence 1, 2, 5, 10, 20, 50, … until the time taken is at least 0.2 second. s/second/seconds/ two times. “seconds” is properly plural elsewhere on the page. Thanks A -- Arthur Goldberg, PhD Mount Sinai Data Warehouse<https://labs.icahn.mssm.edu/msdw/> Scientific Computing and Data<https://labs.icahn.mssm.edu/minervalab/scientific-computing-and-data> Associate Professor of Genetics and Genomic Sciences Institute for Data Science and Genomic Technology Mount Sinai School of Medicine Arthur.Goldberg(a)mssm.edu<mailto:Arthur.Goldberg@mssm.edu> 646 526 5020 Zoom<https://mssm.zoom.us/my/arthur.goldberg?pwd=LzByMGJOZC9wM3A2aHV6OU94eUtSQT09>

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Time module Cheet Sheet
by Karox 29 Jun '23

29 Jun '23

Hello, I was reading Python documentation and testing time module/library and I saw that the time documentation doesn't have capital %D which makes the code view pattern like MM/DD/YY Since I don't know if it's a bug or just a mistake that this directive wasn't put in the table. Or maybe I misread something and it should be like it is. I attach the code down below Best Regards, Karox import time time_object = time.localtime() print(time_object, "\n") vv local_time = time.strftime("%B %d %Y %H:%M:%S", time_object) print(local_time, "\n") vv local_time = time.strftime("%B %D %Y %H:%M:%S %M", time_object) print(local_time, "\n") # OUTPUT: time.struct_time(tm_year=2023, tm_mon=6, tm_mday=29, tm_hour=21, tm_min=21, tm_sec=48, tm_wday=3, tm_yday=180, tm_isdst=1) June 29 2023 21:21:48 June 06/29/23 2023 21:21:48 21

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What happened to the exponent ^ and it's replaced with **?
by Councill, Desurae 25 Jun '23

25 Jun '23

Good morning, I noticed when coding with the latest version of Python 3.11. the exponent ^ bitwise operator does not compute as an exponent? But, if I’m understanding the methods of computation, ^ operand was expressed as a simplistic approach on a calculator to calculate exponents instead of typing out for example 2 x 2 x 2 x 2. Instead it would be written as 2^4 = 16 2*4 would mean 2 x 4 = 8. 2**4 = ????, I mean I guess this good too. When I am computing this 2^4= the answers takes on addition. And adds the two integers. I checked the documents and I don’t see anything about this mentioned in using the operands in Python. Is there anyway I can get feedback about this? When I was learning Python, this was an included operand in relation to exponent expressions. Thank you Desurae Councill Graduate Teaching Assistant School of Information Science and Technology Pennsylvania State University. Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows

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Web page / doc improvement
by Piergiovanni Bazzana 21 Jun '23

21 Jun '23

Hi, I want to submit an improvement, not really a bug but it is smth that may help people that need to deal with large csv files In https://docs.python.org/3/library/csv.html I find in the example the line dialect = csv.Sniffer().sniff(csvfile.read(1024)) while it would be probably better to use smth like: dialect = csv.Sniffer().sniff(csvfile.readline()) because of no magic numbers and cleared rationale behind (I read it as: please try to infer the dialect from the header line of the csv file, which makes a lot of sense) -- Thank you, Best Regards Piergiovanni Bazzana

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