Finding min element using .index() gives unexpected result

Question

I don't understand what is wrong in this list

L = [20,5,4,85,96,75,3,3.1]
m = min(i for i in L if L.index(i)%2==1)

print L.index(m), m

the output as I expected:

7 3.1

but when I change the last number in list 3.1 to 3

L = [20,5,4,85,96,75,3,3]
m = min(i for i in L if L.index(i)%2==1)

print L.index(m), m

the output was not 3:

1 5

please explain the reason

.index finds the *first* index, so neither 3 appears to be at an odd index — jonrsharpe, Jan 01 '20 at 14:27
FWIW for finding the smallest num in an odd index you can just do `min(L[1::2])` see https://stackoverflow.com/questions/509211/understanding-slice-notation — DeepSpace, Jan 01 '20 at 14:36

score 2 · Accepted Answer · answered Jan 01 '20 at 18:35

2

You can use enumerate(), to get position for each value in the list:

L = [20,5,4,85,96,75,3,3]
m = min(j for (i,j) in enumerate(L) if i%2==1)

Output:

6 3

answered Jan 01 '20 at 18:35

Maurice Meyer

1 Answers1