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Why People Should Learn Python

iluxonchik.github.io

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Re: Why People Should Learn Python

#21

Post by joshvm »

Always fun writing compact Python:

    import sys
    from collections import Counter
    
    cnt = Counter([n.strip() for n in sys.stdin.readlines()])
    
    for key, val in cnt.most_common():
        print(val, key)
This isn't just playing code golf, it goes with point (2) - awesome libraries. One of the joys and curses with Python is finding the Pythonic ways to do things that you've hamfistedly written your own way for months.

Re: Why People Should Learn Python

#22

Post by zubspace »

iagooar wrote: post #2

Now that I have a chance to ask: I've always found the def __init__ method with 4 (!) underscores one of the ugliest things I've seen in a programming language. Don't get me wrong: I like Python and know it's truly good, but __why__??

Call me ignorant, but I agree. Having something like __init__ and __new__ is very confusing for a beginner, along with stuff like "__init__.py".

It doesn't stop there: Take something like __str__ and __repr__ combined with str(), repr(), vars(), dir(), print(), pprint.pprint()... I have no idea how anyone ever thought it was a good idea to have that many ways to output the content of a variable. Even after all the time I used python I never managed to find a consistent way to output variable values.

I generally like python as a scripting language. But stuff like this made me constantly lookup obscure details in the documentation which made it very hard for me to completely embrace the language. It also prevented me from diving into more arcane stuff like meta-programming...

Re: Why People Should Learn Python

#23

Post by aidos »

joshvm wrote: post #21

Always fun writing compact Python: import sys from collections import Counter cnt = Counter([n.strip() for n in sys.stdin.readlines()]) for key, val in cnt.most_common(): print(val, key) This isn't just playing code golf, it goes with point (2) - awesome libraries. One of the joys and curses with Python is finding the Pythonic ways to do things that you've hamfistedly written your own way for months.

And you can actually ditch the list comprehension and put it directly in the function call!

    Counter(x for x in y)

Re: Why People Should Learn Python

#24

Post by probably_wrong »

For all its virtues, I feel introductions to Python tiptoe around a very important topic: yes, Python is nice and easy, but you'll have to program the Python way too.

Try running a nested loop on a non-trivial example, and you can end up spending minutes in what would take milliseconds in any other language. If you want to program in Python, you must get used to the functional paradigm. Not "should", "must".

Now, I'm all in for bringing more functional programming into daily life, but I find a bit dishonest that beginners are not told about this. My first serious program took about a week for a task, and shaving that time down involved a lot of pain changing simple nested loops into multiplications of Numpy matrices. There was a lot of caching too. I have no idea how someone without a CS degree would have dealt with this.

Re: Why People Should Learn Python

#25

Post by masklinn »

joshvm wrote: post #21

Always fun writing compact Python: import sys from collections import Counter cnt = Counter([n.strip() for n in sys.stdin.readlines()]) for key, val in cnt.most_common(): print(val, key) This isn't just playing code golf, it goes with point (2) - awesome libraries. One of the joys and curses with Python is finding the Pythonic ways to do things that you've hamfistedly written your own way for months.

FWIW the Counter line can be simplified slightly:

    cnt = Counter(n.strip() for n in sys.stdin)
* no need for a list comprehension, a generator expression will do

* file objects are iterable, and iterated line-wise

Re: Why People Should Learn Python

#26

Post by AhtiK »

greenspot wrote: post #18

Is it just my feeling or are there languages which are preferred on HN? Indicators for languages which are liked by the HN community: - Positive stories get many upvotes and are instantly at the top of HN - Most comments are positive - Frequent coverage on HN about the language Indicators for languages which are not liked by the HN community: - Rants get many upvotes and are instantly at the top of HN - Most comments…

Node.js is a JavaScript runtime, not a language. Used for server-side JavaScript and web frontend build pipeline.

Replacing Node.js with JavaScript doesn't help either as the frontend vs server-side vs npm ecosystem vs es2015 becomes a loaded question .)

Re: Why People Should Learn Python

#27

Post by masklinn »

liaukovv wrote: post #5
iagooar wrote: post #2

Now that I have a chance to ask: I've always found the def __init__ method with 4 (!) underscores one of the ugliest things I've seen in a programming language. Don't get me wrong: I like Python and know it's truly good, but __why__??

So people don't call it directly Defense mechanism of sorts

Also limits chances of conflict with user-defined code.

Re: Why People Should Learn Python

#28

Post by lcnmrn »

hacker_9 wrote: post #19

Why you shouldn't learn Python: 1. In-consistant syntax. 2. The language uses exceptions to control flow of logic. 3. Divided community, since Python 3+ included breaking changes to the standard. 4. Un-discoverable APIs. You better hope the documentation is bulletproof else the API could change in any which way during runtime. 5. Poor error messages. If an import goes wrong you are not told why, and so on. 6. Ultimat…

Name a single language that covers all those things and has a pretty syntax.

Re: Why People Should Learn Python

#29

Post by agounaris »

One my feeling about python is that is a great language for "reference". Probably everybody and write and read it and its already good enough for general programming. There are edges where other languages are better but still is a great language to establish communication among different types of developers

Re: Why People Should Learn Python

#30

Post by pmontra »

iagooar wrote: post #2

Now that I have a chance to ask: I've always found the def __init__ method with 4 (!) underscores one of the ugliest things I've seen in a programming language. Don't get me wrong: I like Python and know it's truly good, but __why__??

Agreed. That, the explicit self argument (which no other major OO language needed) and the : at the end of lines where you would need a { in other languages. If you google you find that there are good reasons for all of those choices but IMHO they are wrong solutions to the problem they solve and make Python look ugly. At least in 2016 they could make the colon optional.

The colon is so ironic for a language that takes pride in replacing braces with indentation. It's there because of readability, see https://docs.python.org/3/faq/design.html#why-are-colons-req... but so, how about an almost Erlang-like full stop?

    if condition:
      statement
      statement.
That would make semantic indentation optional, IDEs and editors know how to reindent code, spare us with bugs introduced by careless copy and paste.

Nevertheless, Python has been widely successful and it's here to stay for a long while. I hope designers will look at those bizarre features and think of better solutions for future languages. Remember that Python has its roots in the 80s. By the standards of the time it was very good. Compare it with the order of magnitudes worse design of PHP, from middle 90s, and there is a lot to forgive to Python. Maybe Guido Van Rossum would make different choices if he were to design his language now, under the influence of the languages of the last 20 years.

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