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| other:python:misc_by_jyp [2023/12/08 16:36] – Added the efficient looping section jypeter | other:python:misc_by_jyp [2024/11/04 15:01] (current) – [Extra tutorials] Added links to ruff and flake8 jypeter |
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| </WRAP> | </WRAP> |
| |
| | ===== Extra tutorials ===== |
| |
| | Only **when you have already read all the content of this page several times**, and you are looking for new ideas |
| | |
| | * [[https://medium.com/pythons-gurus/clean-code-in-python-good-vs-bad-practices-examples-2df344bddacc|Clean Code in Python: Good vs. Bad Practices Examples]] |
| | * [[https://peps.python.org/pep-0008/|PEP 8 – Style Guide for Python Code]] |
| | * [[https://realpython.com/python-pep8/|How to Write Beautiful Python Code With PEP 8]] |
| | * [[https://www.datacamp.com/tutorial/pep8-tutorial-python-code|PEP-8 Tutorial: Code Standards in Python]] |
| | * Some checkers/linters: [[https://docs.astral.sh/ruff/|ruff]], [[https://flake8.pycqa.org/en/stable/|flake8]] |
| | * [[https://medium.com/@yaduvanshineelam09/ultimate-python-cheat-sheet-practical-python-for-everyday-tasks-8a33abc0892f|Ultimate Python Cheat Sheet: Practical Python For Everyday Tasks]] |
| | * [[https://medium.com/pythoneers/16-hacks-that-will-take-your-python-skills-to-the-next-level-12e7a9b97421|16 Hacks That Will Take Your Python Skills to the Next Level]] |
| | * [[https://levelup.gitconnected.com/modular-coding-in-python-finally-solve-your-import-errors-af2fd172fcf7|Modular Coding in Python: Finally Solve your Import Errors]] (understanding and fixing ModuleNotFoundError and ImportError) |
| | * [[https://medium.com/@moraneus/understanding-multithreading-and-multiprocessing-in-python-1ed39bb078d5|Understanding Multithreading and Multiprocessing in Python]] |
| ===== Reading/setting environments variables ===== | ===== Reading/setting environments variables ===== |
| |
| |
| |
| | ===== Using log files (aka logging) ===== |
| | |
| | It is always possible to display information messages using the ''print()'' command, but it is more efficient to use //logging// tools when you want to **display correctly a lot of information about a script progress |
| | ** |
| | * [[https://loguru.readthedocs.io/|Loguru]] is a library which aims to bring enjoyable logging in Python |
| | * See also [[https://betterstack.com/community/guides/logging/loguru/|A Complete Guide to Logging in Python with Loguru]] |
| | * More on [[https://betterstack.com/community/guides/logging/#python|logging with python]] |
| | * The default (but not easy to use) Python ''[[https://docs.python.org/3/library/logging.html|logging]]'' module |
| ===== Stopping a script ===== | ===== Stopping a script ===== |
| |
| ===== Playing with strings ===== | ===== Playing with strings ===== |
| |
| | ==== String formatting ==== |
| | |
| | * Knowing how to display/print a string correctly is always useful for information and debugging purpose |
| | * There are lots of different ways to display strings |
| | |
| | === String formatting examples === |
| | |
| | You will find below some examples of //quick printing//, as well as using //old style formatting//, //formatted string literals (f-strings)// and the //String ''format()'' Method//. More details in the next section |
| | |
| | <code python> |
| | >>> # Basic (but quick and efficient) printing |
| | |
| | >>> year = 1984 |
| | >>> print(year) |
| | 1984 |
| | >>> print('[', year, 'is a famous book ]') |
| | [ 1984 is a famous book ] |
| | |
| | >>> # Old style formatting |
| | |
| | >>> print('[ %i is a famous book ]' % (year,)) |
| | [ 1984 is a famous book ] |
| | >>> print('[ %10i is a famous book ]' % (year,)) |
| | [ 1984 is a famous book ] |
| | >>> print('[ %-10i is a famous book ]' % (year,)) |
| | [ 1984 is a famous book ] |
| | >>> print('[ %010i is a famous book ]' % (year,)) |
| | [ 0000001984 is a famous book ] |
| | |
| | >>> # Formatted string literals (f-strings) |
| | |
| | >>> print(f'[ {year} is a famous book ]') |
| | [ 1984 is a famous book ] |
| | >>> print(f'[ {year=} is a famous book ]') |
| | [ year=1984 is a famous book ] |
| | >>> print(f'[ {year:10} is a famous book ]') |
| | [ 1984 is a famous book ] |
| | >>> print(f'[ {year:<10} is a famous book ]') |
| | [ 1984 is a famous book ] |
| | >>> print(f'[ {year:010} is a famous book ]') |
| | [ 0000001984 is a famous book ] |
| | >>> print(f'[ {year:10.2f} is a famous book (yes, {year}!) ]') |
| | [ 1984.00 is a famous book (yes, 1984!) ] |
| | |
| | >>> # The String format() Method |
| | |
| | >>> print('[ {} is a famous book ]'.format(year)) |
| | [ 1984 is a famous book ] |
| | >>> print('[ {:10} is a famous book ]'.format(year)) |
| | [ 1984 is a famous book ] |
| | >>> print('[ {:<10} is a famous book ]'.format(year)) |
| | [ 1984 is a famous book ] |
| | >>> print('[ {:010} is a famous book ]'.format(year)) |
| | [ 0000001984 is a famous book ] |
| | >>> print('[ {:10.2f} is a famous book (yes, {}!) ]'.format(year, year)) |
| | [ 1984.00 is a famous book (yes, 1984!) ] |
| | >>> print('[ {title:10.2f} is a famous book (yes, {title}!) ]'.format(title=year)) |
| | [ 1984.00 is a famous book (yes, 1984!) ] |
| | >>> print('[ {title:10.2e} is a famous book ]'.format(title=year)) |
| | [ 1.98e+03 is a famous book ]</code> |
| | |
| | === String formatting references === |
| | |
| | * [[https://docs.python.org/3/tutorial/inputoutput.html#formatted-string-literals|Formatted String Literals]] (//f-strings//) |
| | * Available in Python >= 3.6 |
| | * [[https://docs.python.org/3/reference/lexical_analysis.html#f-strings|More documentation]] |
| | * [[https://docs.python.org/3/library/string.html#formatspec|Format Specification Mini-Language]] |
| | * See also the [[https://pyformat.info/|PyFormat site]] |
| | |
| | * [[https://docs.python.org/3/tutorial/inputoutput.html#the-string-format-method|The String format() Method]] |
| | * [[https://docs.python.org/3/library/string.html#formatspec|Format Specification Mini-Language]] |
| | * See also the [[https://pyformat.info/|PyFormat site]] |
| | |
| | * [[https://pyformat.info/|PyFormat site]]: string formatting using the //old style// and the //String ''format()'' method// |
| | * <wrap hi>Hint</wrap>: this can also be used as an **easy documentation for //f-strings// format**! |
| |
| | * [[https://docs.python.org/3/tutorial/inputoutput.html#the-string-format-method|Old string formatting]] |
| ==== Splitting (complex) strings ==== | ==== Splitting (complex) strings ==== |
| |
| |
| |
| ===== Efficient looping with numpy, map and itertools ===== | ===== Efficient looping with numpy, map, itertools and list comprehension ===== |
| |
| <wrap hi>Big, nested, explicit loops should be avoided at all cost</wrap>, in order to reduce a script execution time! | <wrap hi>Big, nested, explicit ''for'' loops should be avoided at all cost</wrap>, in order to reduce a script execution time! |
| |
| * **''numpy'' arrays** should be used when dealing with //numerical data// | * **''numpy'' arrays** should be used when dealing with //numerical data// |
| ... | ... |
| A0$, A0!, A1$, A1!, B0$, B0!, B1$, B1!,</code> | A0$, A0!, A1$, A1!, B0$, B0!, B1$, B1!,</code> |
| | |
| | * The [[https://docs.python.org/3/tutorial/datastructures.html?highlight=comprehension#list-comprehensions|list comprehension]] (aka //implicit loops//) can also be used to generate lists from lists |
| | * Example: converting a list of integers to a list of strings\\ Note: in that case, you should rather use the ''map'' function detailed above |
| | * <code>>>> my_ints = [1, 2, 3] |
| | |
| | >>> [ str(ii) for ii in my_ints ] |
| | ['1', '2', '3']</code> |
| ===== numpy related stuff ===== | ===== numpy related stuff ===== |
| |
| A few notes for a future section or page about about //data representation// (bits and bytes) on disk and in memory, vs //data format// | A few notes for a future section or page about about //data representation// (bits and bytes) on disk and in memory, vs //data format// |
| |
| FIXME Add parts (pages 28 to 37) of this [[https://wiki.lsce.ipsl.fr/pmip3/doku.php/other:python:jyp_steps#part_2|old tutorial]] to this section | FIXME Add parts (pages 28 to 37) of this [[http://www.lsce.ipsl.fr/Phocea/file.php?class=page&file=5/pythonCDAT_jyp_2sur2_070306.pdf|old tutorial]] to this section |
| |
| ==== Base notions ==== | ==== Base notions ==== |
