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Re: Code suggestion - List comprehension

From Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject Re: Code suggestion - List comprehension
Date 2013-12-12 21:55 +0000
References <CALVX-oZZoLzxF5F5-pWwCnGxv1pnHWqxf7-3AP2mE9OEdAcXKQ@mail.gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.4029.1386885377.18130.python-list@python.org> (permalink)

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On 12/12/2013 20:40, Shyam Parimal Katti wrote:
> Hello,
>
> I have a list of sql queries, some which are split across multiple list
> elements e.x.
> ['drop table sample_table;', 'create table sample_test', '(col1 int);',
> 'select col1 from', ' sample_test;']
>
> A semi-colon in the string value  indicates the termination of a sql
> query. So the expected out come is a conversion to a list of valid sql
> queries:
> ['drop table sample_table;', 'create table sample_test (col1 int);',
> 'select col1 from sample_test;']
>
> Here is the code that does that:
>
> sample = ['drop table sample_table;', 'create table sample_test', '(col1
> int);', 'select col1 from', ' sample_test;']
> pure_sqls = []
> query_holder= ''
> for each_line in sample:
>      query_holder += each_line
>      if query_holder.endswith(';'):
>          pure_sqls.append(query_holder)
>          query_holder = ''
>
>
> Is there a way to do this by eliminating explicit creation of new
> list(pure_sqls) and a temporary variable(query_holder)? Using list
> comprehension? Though I don't want to put the shorter version in
> production(if it is difficult to understand), I am looking if this can
> be done with list comprehension since I am trying to learn list
> comprehension by using it in such scenarios.
>

I don't think this can be done with a list comprehension.  As you appear 
to have a perfectly good piece of code, if it ain't broke, don't fix it 
:)  Maybe change one line.

if query_holder[-1] == ';':

-- 
My fellow Pythonistas, ask not what our language can do for you, ask 
what you can do for our language.

Mark Lawrence

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Re: Code suggestion - List comprehension Mark Lawrence <breamoreboy@yahoo.co.uk> - 2013-12-12 21:55 +0000

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