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)
--
DaveA
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