Roberto Bonvallet:
> What output are you expecting from your example matrix? If you are expecting
> it to be 5 (the smallest positive element), using "min" is the way to do it:
> >>> matrix = [[9, 8, 12, 15],
> ... [0, 11, 15, 18],
> ... [0, 0, 10, 13],
> ... [0, 0, 0, 5]]
> >>> min(min(x for x in row if x > 0) for row in matrix)
> 5
This looks a bit like homework...
To find the minimal number > 0 of the matrix this seems better:
mat = [[9, 8, 12, 15],
[0, 11, 15, 18],
[0, 0, 10, 13],
[0, 0, 0, 5]]
print min(el for row in mat for el in row if el > 0)
Note that this raises TypeError is the matrix doesn't have one or more
numbers > 0
If the OP needs the position he/she can do something like:
nozeromin = 1e300 # or something similar
pos = None, None
for nrow, row in enumerate(mat):
for ncol, el in enumerate(row):
if el > 0 and el < nozeromin:
nozeromin = el
pos = nrow, ncol
print nozeromin, pos
Bye,
bearophile
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