2. Run this at the command line:
python -c "print ''.join(list(reversed('!dlrow olleH')))"
- Vasudev Ram - Dancing Bison EnterprisesContact PageWednesday, November 26, 2014
A first Python one-liner
By Vasudev Ram1. Install Python 2.7 (if you don't have it already).
2. Run this at the command line:
2. Run this at the command line:
Subscribe to:
Post Comments (Atom)
9 comments:
Why don't you encourage new users to use Python 3?
print('!dlrow olleH'[::-1])
$ python -c "print ''.join(list(reversed('!dlrow olleH')))"
-bash: !dlrow: event not found
Perfect way to introduce someone to the joys of escaping characters.
Perhaps
python -c "print('dlrow olleH'[::-1])"
is simpler.
Cheers, D.
@Tim Shaffer: That's a good question.
Partly it has been because of the issue of not all libraries having been ported to Python 3 yet, and that there has been a lot of controversy on forums about 2 vs 3, but that has been going on for a while now, and I do know that progress is being made on the porting front. Also, unless more people make the effort (both to use 3 and port stuff to it, things will stay the same). So I think you make a good point, and I'll try to write more about 3 in future, some of the time; I'm not dropping 2 entirely, at least for a while.
@anonymous #!: Yeah, I forgot about sequence slicing and that idiom until after I hit Publish.
Thanks for pointing it out.
I meant Anonymous #1, not #! - call it a Unixian slip :-)
@Anonymous #2:
>Perfect way to introduce someone to the joys of escaping characters.
Thanks for pointing this out. But:
I tested it on Windows, because I was working on that at the time of writing the post. It works fine on Windows. I know about quoting issues on Unix, just didn't run it there. Also see below.
Did you see the labels on the post? "humor"? ... It was not really meant as a tutorial for beginners, just as a quirky hello world one-liner.
Also, caveat lector.
People should not blindly accept any code they see on the Net. Not that I meant the mistake intentionally, of course.
Cheers ...
@Anonymous #1:
>I forgot about sequence slicing and that idiom
I mean, I obviously know slicing, but forgot that negative-stride-of-1 thing:
For those who don't know about slice strides in Python:
https://www.google.co.in/search?q=python%20slice%20stride
Also try these at the Python interpreter prompt:
>>> s = "abcdefghij"
>>> s[-1:0:-3]
'jgd'
>>> s[-1::-3]
'jgda'
>>>
Note the difference in the output between specifiying a 0 vs. not, for the end of the range (the middle number in the square brackets).
Post a Comment