Slice with spice clear solution for First Word (simplified) by veky - python coding challenges

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Slice with spice solution in Clear category for First Word (simplified) by veky

first_word = lambda txt: txt[:(txt+' ').index(' ')]

March 22, 2019

Comments:

mlb00 on April 10, 2019, 3:48 a.m.
Could you explain this code? I just wrote this: <pre class='brush: python'>return text.split(' ')[0] </pre> What is this doing exactly?

veky on April 10, 2019, 3:51 a.m.
Sorry, your question is really too ambiguous. You wrote "this" three times in your question, and I'm quite sure they don't all refer to the same thing. Are you asking about my solution, or yours?

mlb00 on April 10, 2019, 4:02 a.m.
hah! you're right of course. Yes, I'm not sure what your code does exactly. I'm sure what is outputs since it is correct, but now sure how it works, specifically this part: <pre class='brush: python'>txt[:(txt+' ').index(' ')] </pre>

veky on April 10, 2019, 4:08 a.m.
Ah, so lambda is no problem for you. Nice. ;-) Anyway, would you understand what <pre class='brush: python'>txt[:txt.index(' ')] </pre> would do? (Of course, it doesn't work for all inputs, but for those for which it doesn't raise ValueError, it works the same as above.) The slice (in the title) is key. You've probably seen somestring[:5] to extract first five characters from somestring---this is the same, only with variable length. That length is given by the index of (first occurence of) space in txt. So [:...] will slice up to the first space, but not including it. Got it so far? Now, it doesn't work if there is no space in txt. So I add one. ;-]

mlb00 on April 13, 2019, 2:05 a.m.
wow that's really cool. thanks for the very clear explanation!

samipkaarki on June 27, 2020, 1:23 p.m.
@veky i understand all the part except adding space in txt why the code won't work without adding space in txt. Please explain.

veky on June 28, 2020, 2:36 p.m.
Well, first word of "eggs" is eggs, right? But the above can't work since there is no space in "eggs".

bsquare on Sept. 18, 2019, 1:43 p.m.
Quick and nice solution.

xg3572 on May 29, 2020, 3:10 a.m.
Brilliant. Everywhere lambda.

veky on May 29, 2020, 4:12 a.m.
lambda is irrelevant, except for enforcing that the function is an expression, not a statement.

dejans on Aug. 18, 2020, 9:05 p.m.
this is a great way to do it if you want to intimidate your collegues

veky on Aug. 19, 2020, 12:17 a.m.
Well, are you intimidated? :-) I hope not. Have you read the comments?

mohammad.moaddi on Aug. 24, 2020, 7:14 a.m.
Adding " " to resolve returning -1 is brilliant! I think I will be visiting this website more often to see your solutions :)

veky on Aug. 24, 2020, 8:23 a.m.
There is no danger of -1 here. But there is a danger of ValueError. ;-)

vleyked on Sept. 6, 2020, 3:50 a.m.
Great one-liner, but assigning lambdas is not recommended in real-world programming. 'The use of the assignment statement eliminates the sole benefit a lambda expression can offer over an explicit def statement (i.e. that it can be embedded inside a larger expression)' <a href="https://www.python.org/dev/peps/pep-0008/">https://www.python.org/dev/peps/pep-0008/</a>#programming-recommendations EDIT: If I'm correct, there would be an issue if text input has more than one space at the beginning, right? i.e. INPUT: '<more than one space>Hello World' OUTPUT: '<space>'

veky on Sept. 6, 2020, 1:34 p.m.
<h2>PEP8</h2> Yes. And in the real world, I wouldn't use that lambda, because it wouldn't be necessary. I've talked about this many times, you'll probably see it if you stay on CiO long enough (<a href="https://py.checkio.org/mission/binary-count/publications/veky/python-3/hinted/share/7bcd07614f4c5183a12b675c05cceb5d/#comment-42974">example</a>). <h2>Spaces at the beginning</h2> Notice the task text: <blockquote> There aren’t any spaces at the beginning and the end of the string. </blockquote>

rtymoshenko on Dec. 27, 2020, 4:01 p.m.
Nice solution!

_Chico__5d82cee4f5234e78a5c65e on May 15, 2021, 9:22 a.m.
XO

Eusebio_77 on June 24, 2021, 9:46 a.m.
Adding a space at the end is very clever

mondi.s.koci on Sept. 21, 2021, 3:29 a.m.
return text.split(' ').pop(0)

Strings and Integers

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