WTFPython – Understanding Python through surprising snippets

Post by BiteCode_dev » Mon, Dec 23, 2019, 6:58 PM UTC

phlakaton wrote: post #154

BiteCode_dev wrote: post #31

It's a good repo, but remember a lot of those are "A Good Thing™". The first snippet is a very good example: a := "wtf_walrus" doesn't work while: (a := "wtf_walrus") works. It's a fantastic design decision. Python took a long time before getting this operator, because it's a language that favors being readable, easy to use, and above all, to learn. But in many other languages, the very same operator is often misused…

A contrarian's point of view: > The very same operator is often misused as, or confused for, the operator for equality or assignation. It will still be confused, I'm afraid. It's just a little less likely that that confusion will be silently accepted by the interpreter. > Also to hint people at using it only when necessary. Let's be clear: the walrus operator was never, ever, necessary. It's syntactic sugar to avoid…

Post by nickserv » Mon, Dec 23, 2019, 7:02 PM UTC

michaelcampbell wrote: post #137

fxj wrote: post #55

Earlier quoted context omitted.

in the zen of python (import this) it says: there should be one-- and preferably only one --obvious way to do it. sadly this is not true for a while in python now. Python became a language that can be really hard to read now.

As a relative newcomer to Python (compared to most, but I do use it professionally every working day for a year, and some non-working days for personal stuff), I find this to be the case. At work I have to use Django, and it's almost a chore to find anything explicit or obvious in it. Its level of abstraction is "Too Damn High" as the meme goes, IMO. It feels like saving boilerplate for the sake of it which just make…

Post by guitarbill » Mon, Dec 23, 2019, 7:07 PM UTC

doteka wrote: post #157

at_a_remove wrote: post #141

Earlier quoted context omitted.

The many, many ways to print variables inside of a string are testament to that. I remember feeling kind of a chill when the number of methods hit three. Two is an acceptable number of methods if you are transitioning from one form to another as kind of a nod to the growing pains of a language, but at three you have hit some kind of watershed.

There's actually five now! 1. manual string concatenation 2. the old, printf-style. Still heavily used in e.g. stdlib logging module. 3. .format() 4. f-strings 5. string.Template in the stdlib Yup, I definitely see this as one of the bigger failures in Python's design.

Post by xscott » Mon, Dec 23, 2019, 7:59 PM UTC

Scarblac wrote: post #176

xscott wrote: post #167

Earlier quoted context omitted.

Is that what you expected from such a simple piece of code?

Well it's f that has the problem, rather obviously, and the other three lines are unrelated. So I don't see how this is some especially simple way of triggering that error.

    a = 0
    def f():
        print(a)
    f()

    a = 0
    function f() {
        console.log(a)
        a = 1
    }
    f()
    f()

    var a = 0
    def f():
        print(a)
        a = 1
    f()
    f()

Post by h8hawk » Mon, Dec 23, 2019, 8:43 PM UTC

xscott wrote: post #177

Scarblac wrote: post #176

Earlier quoted context omitted.

Well it's f that has the problem, rather obviously, and the other three lines are unrelated. So I don't see how this is some especially simple way of triggering that error.

The other three lines are not unrelated. If you just take the first three lies (and the last one), it's fine: a = 0 def f(): print(a) f() Maybe this is all obvious to you, but I'll bet you can't name any other language which behaves this way. Compare the original Python to JavaScript (or Lua, Perl, Tcl, Ruby, C, Scheme, Rust, Clojure, or ...): a = 0 function f() { console.log(a) a = 1 } f() f() This one behaves how I…

  var a = 9;   
  function foo() {
      console.log(a);
      var a = 12;
  }
  foo();

  $node foo.js
  undefined