Helmut Jarausch a écrit :
> Hi,
>
> I'm looking for an elegant solution of the following tiny but common
> problem.
>
> I have a list of tuples (Unique_ID,Date) both of which are strings.
> I want to delete the tuple (element) with a given Unique_ID, but
> I don't known the corresponding Date.
If you don't care about ordering, you could use a dict:
L=[("a","070501"),("b","080115"),("c","071231")]
d = dict(L)
del d['b']
L = d.items()
But I guess you care about ordering !-)
Anyway, you can still use a dict to find out the date part:
L=[("a","070501"),("b","080115"),("c","071231")]
d = dict(L)
t = ('b', d['b'])
L.remove(t)
Or you could build an 'index' list to find out the appropriate index:
L=[("a","070501"),("b","080115"),("c","071231")]
index = [key for key, val in L]
pos = index.index('b')
del L[pos]
> My straight forward solution is a bit lengthy, e.g.
>
> L=[("a","070501"),("b","080115"),("c","071231")]
> pos=-1
> found=-1
> for (Key,Date) in L :
> pos+= 1
> if Key == "b" :
> found= pos
> break
>
> if found >= 0 :
> del L[found]
>
> print L
You could have used the enumerate(seq) function here. And since you're
breaking out once the element deleted, you could as well delete it from
within the loop:
for pos, (key, date) in enumerate(L):
if key == 'b':
del L[pos]
break
Benchmarking left as an exercice to the reader !-)
Also note that the "best" solution may depend on your real use case and
dataset.
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