Extracting item from list of tuples?
philip at semanchuk.com
Sun Sep 5 19:26:20 CEST 2010
On Sep 5, 2010, at 1:09 PM, Roy Smith wrote:
> I'm using httplib, and want to get the Location header from the
> response. The getheaders() method gives you back a list of (name,
> value) tuples. It would be a lot more convenient if it gave you
> back a
> dict, but it is what it is.
> Anyway, I came up with:
> location = [t for t in headers if t == 'location']
> which works, but is getting on towards the cryptic end of things. Is
> there a better idiom for this?
Are you concerned about efficiency? If it's not important, being less
terse would make it less cryptic:
location = None
for name, value in headers:
if name == "location":
location = value
If you prefer terse, IMHO this is less cryptic (but untested):
location = [value for name, value in headers if name == 'location']
Be careful if you decide to turn the list of tuples into a dictionary.
HTTP headers can repeat and straightforward code to turn the (name,
value) pairs into a dict could end up overwriting data.
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