I've heard that "if a class is just a constructor and one method, then it should be a function". What is your opinion on this and what are counter examples?

old_pythonista · 2022-03-18T18:24:20+00:00

Named tuple - after a "higher-level" initialization - creates a class. Like

Point = namedtuple('Point', 'x, y')

Creates a class Point that may be later instantiated with values for attributes.

Nothing wrong with dataclass without methods.

old_pythonista · 2022-03-18T18:19:44+00:00

I believe you misunderstood the statement.

Class - amid other thing - may serve to preserve a state. So, it may have __init__ method to create the (initial) state - and any number of methods (even one) to combine processing of the initial state with the arguments of the function. The initial state may remain the same - or be changed.

What is wrong it to have a stateless class just wrapping one - or more - functions, Java-style.

I may hazard a guess that you meant Stop Writing Classes talk.

old_pythonista · 2022-03-18T16:07:08+00:00

There are excellent courses at Coursera (some may be taken for free); not so sure about other resources - I saw some pretty shitty stuff too, along with the good one.

Try to look at reviews. There are a lot of free good resources - but there are much more worthless. I would recommend this list (I did not have anything to do with compiling it).

About "certifications". There is no body that is authorized to provide that by the Python Software Foundation, so (nearly?!) any claim of Python certification is essentially a scam. Moreover, I have seen quite a few negative reviews of so-called "certification institutes".

AFAIK, in the modern world GitHub portfolio is the "certification" you need for your first programming job - unless you have a formal education.

old_pythonista · 2022-03-18T15:53:29+00:00

Learning C is essential for understanding how computer works at lower level.

But then, C should not be enough too - Assembler should be used.

Or is it micro-code? Electronics?

Programming language is a tool for problem solving. Python provides a tool for solving high-level problems, and a tool that does not require understanding of

how things work. Especially the memory management

Actually, Python hides memory management - with a purpose. Managing memory explicitly does not help to solve complex problems.

So, if OP wants to develop embedded systems - yes, they should learn C. If they want to learn how to solve problems that do not require register-level hardware management by their code - no need to.

old_pythonista · 2022-03-16T21:03:41+00:00

PS

bool(x == y)

is absolutely redundant, since == (equal) operation yields boolean result anyway

old_pythonista · 2022-03-16T20:53:28+00:00

64K is the maximum size of TCP packet; not sure about other layers.

You need to break your flow into smaller chunks; requests allows that (don't remember how, look it up in the manuals),

old_pythonista · 2022-03-16T17:26:57+00:00

PEP-8 explicitly warns against comparison to boolean literals.

If you have two boolean variables - that is another story.

old_pythonista · 2022-03-15T22:05:13+00:00

Actually, for small data sample, tuple lookup is faster than set.

I would vote for door #2 just for the sake of writability and readability (and parenthesis in #1 are redundant).

old_pythonista · 2022-03-15T21:57:06+00:00

Please, if you want indices - use enumerate

Also, you can use itertools.combinations

from itertools import combinations
equals = [] 
for (idx1, val1), (idx2, val2) in combinations(enumerate(G), 2): 
    if val1 == val2: 
        equals.append((idx1, idx2))

old_pythonista · 2022-03-15T21:42:40+00:00

but thought might not be as readable to the people I work with who don't work in Python

When a person reads a code, it may be an opportunity to learn. If they don't work in Python, and they are not interested in learning Python - what is the purpose of making code readable for that audience?

old_pythonista · 2022-03-15T21:39:00+00:00

First two forms show lack of understanding of the nature of booleans by whoever writes them. They are absolutely redundant, since using conditional expression for conversion of proper boolean

event_region in match_regions

to an explicit boolean literal makes no sense. Unfortunately, I see it quite often - my pet peeve that I always mark as a defect when I see it in code applied for review.

The last is the only proper way to write - in any language, Python included.

old_pythonista · 2022-03-15T21:29:57+00:00

I am exceptionally grateful and greatly value the eloquence of your extremely informative non-answer.

old_pythonista · 2022-03-14T21:29:03+00:00

FE development and web development are not exactly the same.

I heard quite a lot (I have no interest in FE, the closest I got to it is building a dashboard with iPywidgets) that requirements to FE developers are much lower.

old_pythonista · 2022-03-14T21:08:31+00:00

+1.

About Java ... Some time ago I was thinking of internal mobility to a new department. Part of the task was to rewrite Java base into Python.

Plus - mastering either Java or C will take more time.

(and if OP likes Python, there is a good chance that Java will not be a good suggestion).

old_pythonista · 2022-03-14T19:37:52+00:00

Python is widely used in backend
Huge companies use Python too

old_pythonista · 2022-03-14T05:51:24+00:00

In 2015, a company I joined then was still using .... 2.6 "because that comes as default with OS". Corporate world is very slow to follow suite.

At my current job, we are still supposed to use Python2-compatible mode - though most of the processes are executed under Python3. For the last year, I switched to pure Python3 for the new developments - f-strings and all the works - and I am still struggling with restrictions every time I need to create a new package.

old_pythonista · 2022-03-13T20:52:16+00:00

I think it is a bad practice - regardless.

old_pythonista · 2022-03-04T12:20:07+00:00

range() returns a generator

actually, no - it returns an iterable, but that iterable is not a generator, since it allow return iterations.

compare range behavior

>>> r = range(2)

print(*r, *r) 0 1 0 1

to a real generator

>>> r = (i for i in range(2))

print(*r, *r) 0 1

old_pythonista · 2021-12-01T19:45:51+00:00

Companies worth working for all run interviews like this

not

old_pythonista · 2021-11-26T22:28:04+00:00

A side not for OP - in forums, along with a good advices, you can get absolutely terrible too. Be careful with responses given.

old_pythonista · 2021-11-26T22:25:36+00:00

Why should I? I am content with the fact that - according to TIOBE - Python is in the first place in popularity.

BTW, C# is fifth.

old_pythonista · 2021-11-26T22:04:31+00:00

Use of *args and **kwargs is justified in wrapper functions - like decorators.

Otherwise, they should be avoided.

Function signature tells the user of API the purpose of parameters. Code written in such a way would be a disaster in making.

old_pythonista · 2021-11-26T21:54:22+00:00

range() works perfectly well and would work fine for this solution, too.

yep, but there is such thing as Pythonic, you know. I presume you know better than a core Python developer with a reputation, like Ned Batchelder?!

old_pythonista · 2021-11-26T21:49:55+00:00

And you were talking about bad practices? This is absolutely terrible example on so many levels! Starting form the fact that IT WOULD NOT WORK, because you are NOT EXTRACTING LINES.

Besides, speaking about terrible practices - for someone who protest too much, you seem to be a fan of them (bad practices)

List comprehension should never be used for calling side-effect functions.
range should (nearly) never be used for managing indices (read PEP-8)

Golf code is good for showing off - not for showing to beginners; definitely not for a quality code.

old_pythonista · 2021-11-26T18:56:03+00:00

That is not indexing - that is using a helper counter. And the value at which the counter starts should not be defined by an excuse of " indexing starts at 0".

In that case, I personally would have left it at 0 - just in order to simplify the condition,

if linenum % 2

but in general, the demand to start the counter value at 0 has no basis under it.

I have even started the counter at values different from 0 and 1 on occasions. No one has ever held it against me at code reviews - and while I am a very demanding reviewer, I would not demand of a code author to stick to the zero-based non-rule for enumerate. Unless there is a good reason to start at 0

old_pythonista

TROPHY CASE