Mailman 3 September 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 Moreover, while looking for a solution I noticed a lot of articles with outdated examples which no longer work - this confused me even more to the point I started suspecting something was amiss on my end...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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about deprecated document
by SUN Guonian 09 Nov '23

09 Nov '23

hi, When I browse subprocess document on (https://docs.python.org/3.11/library/subprocess.html) I find some piece about "Replacing os.popen(), os.popen2(), os.popen3()", but I can't find any popen3() in module os, untill I search the document to version 2.7. Maybe the content related to the deprecated document should be cleaned in the latest version. Best Regards, SUN Guonian

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Problem in help for str().rsplit()
by Alan Brogan 09 Nov '23

09 Nov '23

Greetings to the list Not sure where this report should be sent, so I’m hoping the good people on this list can help to forward it on. The docs suggest I should distinguish a bug as being either of the docs, or of the implementation, but this one is in the docstring of the function, so which does that count as??? What I would call "the docs” (https://docs.python.org/3/library/stdtypes.html?highlight=rsplit#str.rsplit <https://docs.python.org/3/library/stdtypes.html?highlight=rsplit#str.rsplit>) explains the function differently, and is (AFAICT) correct Problem is in docstring for the str().rsplit() method: >>> help(str().rsplit) Help on built-in function rsplit: rsplit(sep=None, maxsplit=-1) method of builtins.str instance Return a list of the substrings in the string, using sep as the separator string. sep The separator used to split the string. When set to None (the default value), will split on any whitespace character (including \\n \\r \\t \\f and spaces) and will discard empty strings from the result. maxsplit Maximum number of splits (starting from the left). -1 (the default value) means no limit. Splitting starts at the end of the string and works to the front. Problem is at the phrase "(starting from the left)” I think that should actually say “starting from the right”, because >>> s = "alan was here today" >>> s.rsplit(" ", 1) ['alan was here', 'today'] -- Alan

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Errors in 3.11.4 EPUB version
by Ranjith B 09 Nov '23

09 Nov '23

Dear Python community, The EPUB version for 3.11.4 is not readable. Each page contains errors like the following: “This page contains the following errors: error on line 22 at column 19: Specification mandates value for attribute defer Below is a rendering of the page up to the first error.” Please fix the issue. Thank you, Best Regards, Ranjith

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EPUB version of documenation
by Glenn Street 09 Nov '23

09 Nov '23

Hi! When I try to open the EPUB version of the Python documentation from Download Python 3.11.4 Documentation <https://docs.python.org/3/archives/python-3.11.4-docs.epub> using Apple’s Books program, i get the following error on every page. Please advise. Best wishes, Glenn Street

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Data type range printed wrong ?
by Shivansh Verma 09 Nov '23

09 Nov '23

https://docs.python.org/3/library/array.html In the above given url which lead to a page of array module in documentation, on that page a table regarding the typecodes of the array is given, in that table the size range of the signed and unsigned int of typecode "i" is given as 2 bytes which I think should be 4 bytes instead, as even using that data type on an array and using function itemsize() on it also return 4 bytes. Though I do have some confusion regarding the column 'minimum size in bytes' of the table, does minimum size in bytes means something other than the range of that data type in bytes? If in case that is actually an error and minimum size in bytes means the range of data types in bytes than I would request you to please have a look at it, else I apologise for this mail and wasting your time in advance, but please let me know what does the minimum data size in bytes actually mean then, and why it is 2 bytes instead of 4 bytes for signed and unsigned int of typecode "i".

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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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Howto/regex omits the simplest {n} case
by Derek Mead 30 Oct '23

30 Oct '23

Hi, https://docs.python.org/3/howto/regex.html#repeating-things states: *You can omit either m or n; in that case, a reasonable value is assumed for the missing value. Omitting m is interpreted as a lower limit of 0, while omitting n results in an upper bound of infinity.* This is correct, for the cases of {m,} and {,n}. What isn't covered is the simplest case {m} which matches the preceding item exactly m times. Regards, Derek PS https://docs.python.org/3/howto/regex.html is generally one of the best bits of software documentation I have come across: it's a model of simplicity and clarity, on a notoriously difficult topic.

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