(a==b) ? 'Yes' : 'No'
in [Python]
|
From: Steve Holden on 30 Mar 2010 16:32 Robert Fendt wrote: > And thus spake John Bokma <john(a)castleamber.com> > Tue, 30 Mar 2010 13:19:19 -0600: > >> And >> >> a == b and 'Yes' or 'No' >> >> isn't a Perl-ism? > > I never said that this would be better. I don't even get the > point of what the advantage is supposed to be of inverting the > order of the return statement and the conditional check what > should actually _be_ returned. What's wrong with just writing > > if a==b: > return 'Yes' > else: > return 'No' > > apart from it being a few more line breaks and an additional > return statement? The inverted form is not more readable per > se (in fact, quite the opposite), and I would even suggest to > minimise its use even in languages like C++ and Java. The Python > syntax is even worse since it not only inverts the order of > return statement and conditional check, but it also puts the > conditional between the two results. > > I find such a convoluted construct especially ugly in a language > which I previously regarded as having a rather striking beauty > of syntactical simplicity. The construct is superfluous, > illogical, unelegant, and thus very un-pythonesque, IMHO. But of > course that's just my $0.02. > >> Sheesh, this group would be so much nicer without the constant dragging >> in of Perl to make a point. On top of that, do { } unless blocks are >> not idomatic in Perl. Perl Best Practices even clearly states to *never* >> use unless. > > Sorry, but you have just underlined my point, in fact. If it's > discouraged by experts, then of course the question must be > valid why such a feature even exists (okay, apart from 'it > seemed like a good idea at the time'). And more importantly (and > more on-topic here), why we have to have an analogon in Python. It exists because people nagged Guido mercilessly until, against his better judgment, he capitulated. regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 See PyCon Talks from Atlanta 2010 http://pycon.blip.tv/ Holden Web LLC http://www.holdenweb.com/ UPCOMING EVENTS: http://holdenweb.eventbrite.com/
From: MRAB on 30 Mar 2010 17:43 Robert Fendt wrote: > And thus spake John Bokma <john(a)castleamber.com> > Tue, 30 Mar 2010 13:19:19 -0600: > >> And >> >> a == b and 'Yes' or 'No' >> >> isn't a Perl-ism? > > I never said that this would be better. I don't even get the > point of what the advantage is supposed to be of inverting the > order of the return statement and the conditional check what > should actually _be_ returned. What's wrong with just writing > > if a==b: > return 'Yes' > else: > return 'No' > > apart from it being a few more line breaks and an additional > return statement? The inverted form is not more readable per > se (in fact, quite the opposite), and I would even suggest to > minimise its use even in languages like C++ and Java. The Python > syntax is even worse since it not only inverts the order of > return statement and conditional check, but it also puts the > conditional between the two results. > > I find such a convoluted construct especially ugly in a language > which I previously regarded as having a rather striking beauty > of syntactical simplicity. The construct is superfluous, > illogical, unelegant, and thus very un-pythonesque, IMHO. But of > course that's just my $0.02. > I think you mean that it's very _un-Pythonic_ (perhaps because it's very very Pythonesque)! :-) >> Sheesh, this group would be so much nicer without the constant dragging >> in of Perl to make a point. On top of that, do { } unless blocks are >> not idomatic in Perl. Perl Best Practices even clearly states to *never* >> use unless. > > Sorry, but you have just underlined my point, in fact. If it's > discouraged by experts, then of course the question must be > valid why such a feature even exists (okay, apart from 'it > seemed like a good idea at the time'). And more importantly (and > more on-topic here), why we have to have an analogon in Python. >
From: Robert Fendt on 30 Mar 2010 17:47 And thus spake MRAB <python(a)mrabarnett.plus.com> Tue, 30 Mar 2010 22:43:04 +0100: > I think you mean that it's very _un-Pythonic_ (perhaps because it's very > very Pythonesque)! :-) Yes. Of course. What was I thinking. ;-) Regards, Robert
From: Stephen Hansen on 30 Mar 2010 18:17 On 2010-03-30 13:16:00 -0700, Robert Fendt said: > > I find such a convoluted construct especially ugly in a language > which I previously regarded as having a rather striking beauty > of syntactical simplicity. The construct is superfluous, > illogical, unelegant, and thus very un-pythonesque, IMHO. But of > course that's just my $0.02. In Python before list-comprehensions, I might have agreed with you. Initially, I was quite resistant to list comprehensions as well. They seemed ugly, and backwards, and why not just write a for loop? Then I got used to them, and I find they are very elegant when used properly. Sometimes you can do something ugly with them, but its actually quite possible to write positively hideous Python even without any of these new fancy shmancy features. But, in the post-comprehension world, where one can do: my_odds = [x for x in range(100) if x % 2 == 1] Things have changed. I've now grown used to reading expressions like that which seem a bit backwards, with the value being returned by an expression is the left-most element. Its not an exact correlation because they're answering different problems. But having gotten used to list comprehensions, and actually quite appreciating their elegance now, I find this reads very well: is_odd = "odd" if x % 2 == 1 else "even" In fact, it reads better then any of the other conditional expression syntaxes people proposed back in the day, and a LOT better then what was done before: is_odd = x % 2 == 1 and "odd" or "even" Even if the above falls a bit more in line with what other languages usually do order-wise, this isn't other languages. Now, none of this addresses your original argument of why not just use a regular if statement. I dunno, I often used "and/or" for simple expressions or defaults and found it very convienent and made code more readable then the line and whitespace inducing true if-statement. And so I'm glad to have something even more readable and without the bug-prone and/or error. Why not just use a for loop anytime you use a list comprehension? :) Same question really applies. -- --S .... p.s: change the ".invalid" to ".com" in email address to reply privately.
From: Lawrence D'Oliveiro on 30 Mar 2010 19:18
In message <7316f3d2-bcc9-4a1a-8598- cdd5d41fd74b(a)k17g2000yqb.googlegroups.com>, Joaquin Abian wrote: > (a==b) and 'YES' or 'NO' > > Yes, ugly Why would you say that's ugly? By the way, you don't need the parentheses. |