On 11/28/14, Dave Angel <da...@davea.name> wrote:
> On 11/28/2014 10:04 AM, fetchinson . wrote:
>> Hi all,
>>
>> I have a feeling that I should solve this by a context manager but
>> since I've never used them I'm not sure what the optimal (in the
>> python sense) solution is. So basically what I do all the time is
>> this:
>>
>> for line in open( 'myfile' ):
>> if not line:
>> # discard empty lines
>> continue
>> if line.startswith( '#' ):
>> # discard lines starting with #
>> continue
>> items = line.split( )
>> if not items:
>> # discard lines with only spaces, tabs, etc
>> continue
>>
>> process( items )
>>
>> You see I'd like to ignore lines which are empty, start with a #, or
>> are only white space. How would I write a context manager so that the
>> above simply becomes
>>
>> with some_tricky_stuff( 'myfile' ) as items:
>> process( items )
>>
>
> I see what you're getting at, but a context manager is the wrong
> paradigm. What you want is a generator. (untested)
>
> def mygenerator(filename):
> with open(filename) as f:
> for line in f:
> if not line: continue
> if line.startswith('#'): continue
> items = line.split()
> if not items: continue
> yield items
>
> Now your caller simply does:
>
> for items in mygenerator(filename):
> process(items)
Great, thanks a lot!
Cheers,
Daniel
>
> --
> DaveA
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