Python tip of the week - Githubissues

MTG / pymtg

Python research utils that some of us use at the MTG and eventually everyone will use :)

https://mtg.github.io/pymtg/

MIT License

7 stars 1 forks source link

Python tip of the week #4

Open alastair opened 5 years ago

alastair commented 5 years ago

Some suggestions of tips to email people about how to do things better in python

[x] Use python 3
[ ] How to do stylechecks using your favourite editor
[x] Use time.monotonic() to count how long something takes
[ ] Use concurrent.futures for multiprocessing [ffont] I have a utility class for this in pymtg based in concurrent.futures. we can talk about that. I guess I could do this tip
[x] Use sets or dictionary keys to check membership when in loops
[x] collections.defaultdict
[x] collections.Counter
[x] os.path.join or Pathlib instead of concatenating paths with + '/' +
[ ] Argument parsing / Fire
[x] CSV module instead of constructing by hand
[ ] enumerate
[x] dict.items
[x] zip
[ ] sorting

LPorcaro commented 5 years ago

I like to use pyflakes for checking my code while testing https://pypi.org/project/pyflakes/ Maybe it can be in the same tip with stylechecks (even if it is not properly a stylecheck)

jordipons commented 5 years ago

student_tuples = [ ('john', 'A', 15), ('jane', 'B', 12), ('dave', 'B', 10), ] sorted(student_tuples, key=lambda student: student[2]) # sort by age [('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]

Sort with the lambda function. https://wiki.python.org/moin/HowTo/Sorting

alastair commented 5 years ago

sorting is a great item! especially using lambdas or the operator module for the key parameter.

xavierfav commented 5 years ago

More suggestions:

[ ] *args and **kwargs
[ ] Avoid running out of memory with Generators
[ ] for/else
[ ] Classes
[ ] Reduce RAM usage & make attribute accesses faster with __slots__ (https://habr.com/en/post/458518/)
[ ] Variable scope

wuaalb commented 5 years ago

[ ] conda package/environment manager
[x] collections.OrderedDict (note dict ordered in CPython 3.6 and dict ordered in 3.7 language)
[x] f-strings (3.6+)
[ ] itertools (e.g. example below)
[ ] numba jit compiler
[ ] pysoundfile (libsndfile wrapper) for audio file i/o
[ ] resampy for resampling
[ ] pytoml / TOML for config files
[ ] logging

example of splitting note sequence into phrases using itertools.groupby:

>>> import itertools
>>> notes = ['sil', 'g', 'g', 'd', 'd', 'e', 'e', 'd', 'sil', 'c', 'c', 'b', 'b', 'a', 'a', 'g', 'sil']
>>> phrases = []
>>> for is_sil, group in itertools.groupby(notes, key=lambda note: note == 'sil'):
...     if not is_sil:
...         phrases.append(list(group))
... 
>>> print(phrases)
[['g', 'g', 'd', 'd', 'e', 'e', 'd'], ['c', 'c', 'b', 'b', 'a', 'a', 'g']]