Matt Nordhoff <[EMAIL PROTECTED]> wrote:
> Using two list comprehensions mean you construct two lists, which sucks
> if it's a large file.
Only if it is very large. You aren't duplicating the data except for
entries with whitespace round them. If there isn't a lot of whitespace then
the extra overhead for duplicating the list is unlikely to be significant.
>
> Also, you could pass the list comprehension (or better yet a generator
> expression) directly to dict() without saving it to a variable:
>
> with open('/etc/virtual/domainowners','r') as fh:
> return dict(line.strip().split(':', 1) for line in fh)
>
> (Argh, that doesn't .strip() the key and value, which means it won't
> work, but it's so simple and elegant and I'm tired enough that I'm not
> going to add that. :-P Just use another genexp. Makes for a line
> complicated enough that it could be turned into a for loop, though.)
It isn't hard to convert my lists to generators keeping the structure
exactly the same (and fixing the typo):
def loaddomainowners(domain):
with open('/etc/virtual/domainowners','r') as infile:
pairs = (line.split(':',1) for line in infile if ':' in line)
pairs = ((domain.strip(), owner.strip())
for (domain,owner) in pairs)
return dict(pairs)
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