try items[items.index(border):] clear solution for Remove All Before by Olpag - python coding challenges

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try items[items.index(border):] solution in Clear category for Remove All Before by Olpag

def remove_all_before(items, border):
    try:
        return items[items.index(border):]
    except ValueError:
        return items

Jan. 30, 2020

Comments:

trinux89 on April 5, 2020, 4:22 p.m.
Excellent!!!

Dichra on June 10, 2020, 7:23 p.m.
Wow nice!

zhulanov_anton_c3c46b6e60c5441 on July 28, 2020, 7:54 p.m.
In this case using exception is more valuable memory operation than conditional

yuxihang99 on Oct. 9, 2020, 1:57 a.m.
How to use Iterable?

tildebyte on Jan. 8, 2021, 2:24 p.m.
If you're asking why `Iterable` is imported: it's to allow annotating `Iterable` as the return type in <pre class='brush: python'>def remove_all_before(items: list, border: int) -> Iterable: </pre>

Shiiiiiin on Oct. 11, 2021, 9:50 a.m.
from typing import Iterable

xiaoyangli.cityu on Oct. 10, 2020, 11:55 a.m.
Nice shot!

Java_Win on Oct. 15, 2020, 2:25 p.m.
i think exception for logic is not ok

tildebyte on Jan. 8, 2021, 2:22 p.m.
This is incorrect. Using exceptions for control flow is very idiomatic -- for Python.

samhuawey on Dec. 4, 2020, 10:29 a.m.
Exception handling may be not the best solution in terms of efficiency. I guess border in items may be way faster.

Olpag on March 21, 2021, 12:18 a.m.
<a href="https://docs.python.org/3/glossary.html">https://docs.python.org/3/glossary.html</a> <blockquote> EAFP Easier to ask for forgiveness than permission. This common Python coding style assumes the existence of valid keys or attributes and catches exceptions if the assumption proves false. This clean and fast style is characterized by the presence of many try and except statements. The technique contrasts with the LBYL style common to many other languages such as C. </blockquote>

Dascal on March 30, 2022, 10:08 p.m.
Does efficiency of exception handling depend on frequency of exceptions? I mean if we have a lot of cases with exception it is better to use if statement?

Olpag on Aug. 15, 2022, 1:24 p.m.
<a href="https://py.checkio.org/mission/remove-all-before/publications/Olpag/python-3/try-itemsitemsindexborder/share/5e8f879578c474b95b3ceee4fbbf4cf1/">https://py.checkio.org/mission/remove-all-before/publications/Olpag/python-3/try-itemsitemsindexborder/share/5e8f879578c474b95b3ceee4fbbf4cf1/</a>#comment-105107

mu_py on Oct. 9, 2022, 12:51 p.m.
Thanks for pointing to the docs. It's an important information for Python-newbies.

gudishvibes2 on Dec. 31, 2020, 11:30 p.m.
slicing. genius.

xiaoxiannv-TangTang on Jan. 1, 2021, 12:09 a.m.
Nice solution using the try, except. It inspires me to use try/except to handle cases where logic conditions are not met. =)

Lemur21 on Jan. 4, 2021, 9:59 p.m.
This is a really clear solution!

ramk971995 on Jan. 27, 2021, 12:46 a.m.
I think Code has to be readable clear and concisely

hyewonkim on Jan. 27, 2021, 4:29 a.m.
Wow it's cool

myusercb on Feb. 26, 2021, 4:20 p.m.
Using exception for flow control is not recommended. This is not a good practice.

mccoy on July 24, 2021, 4:30 p.m.
Not true. But it is certainly good practice to at least glimpse over other comments <a href="https://py.checkio.org/mission/remove-all-before/publications/Olpag/python-3/try-itemsitemsindexborder/share/5e8f879578c474b95b3ceee4fbbf4cf1/#comment-94133">where this objection had been discussed already</a>.

minhbong22 on March 3, 2021, 3:25 p.m.
nice

modernist888 on March 12, 2021, 1:42 p.m.
It's great! How much practice does it take for such decisions to come?)

Olpag on March 12, 2021, 10:08 p.m.
It was a thorny path... Half a life or more )

marat.m on March 14, 2021, 1:36 a.m.
Interesting way of using exception handling for flow control

nagadeepak511 on March 18, 2021, 4:34 a.m.
Cool

Fresh-Man-Boy on March 20, 2021, 12:56 a.m.
wo cao?

_Chico__5d82cee4f5234e78a5c65e on May 16, 2021, 2:55 p.m.
Wow, this is a Great solution! Never thought of this way!

deerbeck on May 27, 2021, 5:41 a.m.
This is a very elegant way of solving the problem!

leggewie on June 25, 2021, 9:55 p.m.
learned a lot from the code as well as the comments. thanks, guys!

pocketok on July 1, 2021, 3:03 p.m.
I would rename a long variables to make a code even more concise: items -> a, border -> n

mccoy on July 24, 2021, 4:31 p.m.
I find that degrades readability, but to each their own.

gamer995 on July 6, 2021, 10 a.m.
like

lawestown on Aug. 3, 2021, 7:14 a.m.
I've learned a lot about using "try" to solve cases where "items" are empty.

viktor.chyrkin on Aug. 9, 2021, 3:46 p.m.
cool!

ViceTwice on Aug. 19, 2021, 2:20 p.m.
Too slow, just use "if" instead of handling exception: <pre class='brush: python'>def remove_all_before(items, border): if (border in items): return items[items.index(border):] else: return items </pre>

Olpag on Aug. 19, 2021, 8:14 p.m.
<blockquote> Too slow </blockquote> Are you sure about this? First, it would be nice to read the <a href="https://py.checkio.org/mission/remove-all-before/publications/Olpag/python-3/try-itemsitemsindexborder/share/5e8f879578c474b95b3ceee4fbbf4cf1/#comment-98159">my comment above</a> Secondly, you can test the performance using the timeit library: <pre class='brush: python'>import timeit try_except = """ def remove_all_before(items, border): try: return items[items.index(border):] except ValueError: return items remove_all_before([1, 2, 3, 4, 5], 3) """ if_statement = """ def remove_all_before(items, border): if (border in items): return items[items.index(border):] else: return items remove_all_before([1, 2, 3, 4, 5], 3) """ </pre> check the result: <pre class='brush: python'>>>> min(timeit.repeat(stmt=try_except)) 0.30905460000000007 >>> min(timeit.repeat(stmt=if_statement)) 0.34901209999999994 >>> </pre>

Olpag on Aug. 19, 2021, 8:59 p.m.
It all depends on the situation The "tryexcept" will be faster if the border does exist, but will be much slower if it doesn't exist. If border almost always exists, you go with the "tryexcept". Otherwise, the "if_statement" works better.

ITholmes on Aug. 25, 2021, 6:07 p.m.
nice solution

klambotskii on Sept. 3, 2021, 7:01 a.m.
Olpag, your solution very good!

hbczmxy on Oct. 1, 2021, 11:57 a.m.
list.index will return first index of value. But it will raise ValueError if the value is not present. So we use "try" to catch ValueError. If everything is normal, it execute try block. If list.index raise ValueError, "try" will catch ValueError then execute except block.

Olpag on Oct. 2, 2021, 8:05 a.m.
yes

Himawari7_740892e5105345abb331 on Oct. 5, 2021, 7:39 a.m.
すばらしい！、いつも他の人のコードを見るのは勉強になります。私もあなたのようなコードが書けるようになりたいです

Olpag on Oct. 6, 2021, 7:59 a.m.
もっと練習。そして、あなたは成功するでしょう。しかし、ここでは英語でコミュニケーションをとるのが通例です。

Himawari7_740892e5105345abb331 on Oct. 6, 2021, noon
ポイントの為にコメントしただけだからどうでもいいんだよ

Olpag on Oct. 6, 2021, 8:18 p.m.
ĝi ne estas ĝentila al aliaj

Carmine on Oct. 7, 2021, 11:31 a.m.
nice

lexxPR on Oct. 7, 2021, 2:38 p.m.
not bad

martavohnoutova on March 1, 2022, 3:41 p.m.
Nothing against. I like this solution, I mean it is Pythonic :-)

Han_Liu on May 12, 2022, 1:38 a.m.
Great!!

vincentfullfillthedream on Aug. 30, 2022, 6:31 a.m.
nice

Yunus_Karimboyev on Oct. 14, 2022, 8:43 a.m.
zo'r

alex-z-98 on Dec. 5, 2022, 6:10 p.m.
Noice

universetoday on Aug. 19, 2024, 7:18 a.m.
This function efficiently uses index() to find the position of border and slice the list accordingly. The use of try-except to handle the ValueError is appropriate and prevents the function from crashing if border is not found. However, it might be worth noting that handling exceptions in performance-critical code can be costly, so it could be better to check if border exists first with an if statement. But for most cases, this solution is clear, concise, and effective.

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