pass clear solution for Simplify Unix Path by veky - python coding challenges

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pass solution in Clear category for Simplify Unix Path by veky

def simplify_path(path):
    segments = path.split('/')
    absolute = not segments[0]
    result = []
    for segment in segments:
        if '.'.startswith(segment): pass
        elif segment != '..': result.append(segment)
        elif result and result[~0] != '..': del result[~0]
        elif not absolute: result.append(segment)            
    return '/'*absolute + '/'.join(result) or '.'

Aug. 1, 2017

Comments:

veky on Aug. 1, 2017, 8:57 a.m.
Kernighan says "flatten your if/else chains". Judge for yourself whether this makes clearer code. :-)

oduvan on Aug. 1, 2017, 3:22 p.m.
what is the difference between <pre class='brush: python'>del result[~0] </pre> and <pre class='brush: python'>del result[-1] </pre> ?

veky on Aug. 1, 2017, 8:33 p.m.
I find it more intuitive to start from 0 on both ends. If you delete first element with del result[0], but you delete last one with del result[-1], you invite weird off-by-one errors.

R2R on Nov. 27, 2017, 7:53 p.m.
Very elegant solution! Just 1 question. Why using <pre class='brush: python'>if '.'.startswith(segment) </pre> instead of more readable <pre class='brush: python'>segment in ('.','') </pre> ?

veky on Nov. 28, 2017, 11:37 a.m.
Because to me the former is more readable? :-) In fact, I wanted to say, "if segment is a prefix of '.'", but the closest I could get in Python was the above.

R2R on Nov. 30, 2017, 6:43 p.m.
It just became more interesting after your clarification! How did you come to the sentence "if <some char string> is a prefix of <one char>"? By human-thinking logic it means a set of (<one char> and <empty string>). Since only these two can be "prefix"... Are you a human? :) If so you must be genious!

veky on Dec. 1, 2017, 6:12 a.m.
<blockquote> How did you come to the sentence "if <some char string> is a prefix of <one char>"? </blockquote> In my view, "one char" is just a special case. In various path-handling code, you need to treat `''`, `'.'` and `'..'` segments as special. And I'm pretty sure that if you could have `'...'`, it would also be treated specially. (see, e.g. Python relative imports:). Of course, the nicest would be if you had a function "consistsonlyof_dots" (`set(segment) <= {'.'}` - I love those spontaneous smileys in the code;), but since the length is limited anyway, "is a prefix of `'.'*n`" is good enough. Am I a human? There's still heated <a href="https://py.checkio.org/mission/i-love-python/publications/veky/python-3/magnum-opus/#comment-27134">discussion</a> about that. :-D But genious... only by a very weak criteria of "thinking differently than most people".

R2R on Dec. 1, 2017, 7:50 p.m.
You definitely think differently! And it's dazzling to analyze your solutions. Thanks! P.S. And what about another month you was given for F# in that "heated discussion"? Will this story be continued? :)

veky on Dec. 2, 2017, 6:55 a.m.
<blockquote> And what about another month you was given for F# in that "heated discussion"? </blockquote> Actually, that was another heated discussion. There are lots of them, and sometimes they interleave. :-D <blockquote> Will this story be continued? :) </blockquote> I doubt it. I think we have said all we wanted to say there. hanpari was probably very happy that something like F# exists, and tried to share the enthusiasm. In the meantime I think even he realized that it's really nothing special. But if you have a sweet tooth for heated discussions between me and hanpari, you should check out <a href="https://py.checkio.org/mission/pangram/publications/asa119/python-3/first/share/074fd8ceec0ec9074e5d667a20a7b413/#comment-24645">this one</a>. Be warned, it's long. :-D

R2R on Dec. 2, 2017, 8:52 p.m.
It's really long. And most interesting in this discussion is your statement that you have no mobile phone! Is it true?

veky on Dec. 3, 2017, 6:47 a.m.
Ah, if that you find most interesting, then I probably failed. :-Q Anyway, yes, it's true. Disclaimer: recently I got myself a tablet with an internet card that can connect to GPRS network (having two kids kinda requires you to be always online:), so it can be called a "mobile internet device", but not a "phone" since you can't make calls on it (except on things like Hangouts, and that's really expensive:).

R2R on Dec. 5, 2017, 7:24 p.m.
I'm lost with ideas. As you wrote you love metropoli I dare to conclude that you live in the big city. And you have family, you have job... How do they reach you with no mobile phone? The only idea is that you spend most of time at home and use wire phone. And that's interesting. But you didn't fail with that long-read discussion. It's obvious from first two posts there that you are two heads above your opponent. That's why there's nothing really new reading how you iteratively explain the simple things.

veky on Dec. 5, 2017, 8:06 p.m.
Well, Zagreb is not so big. :-) But yes, as I said, when my older son started school, I was practically forced to get a mobile Internet device. But still no phone. :-P Yes, I do spend most of time at home, but the only people who call me on landline are people who don't use the Internet (and yes, I hang around with some of these, too;). And those things I explain might be simple to you, but many people told me they had valuable insights reading them. I'm sure I'll find something to teach you, too, with time. :-)

StefanPochmann on Dec. 3, 2017, 3:13 p.m.
<blockquote> <pre class='brush: python'>segment in ('.','') </pre> </blockquote> No need for so much code, you can just use <pre class='brush: python'>segment in '.' </pre>

R2R on Dec. 5, 2017, 7:16 p.m.
Stefan you're right! Cute!

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