How can I sort a list and print the second largest element in it using python 3?

Question

List sorting in python
I'm getting a Nonetype error

Answer 1

you can do it in a way like this:

x=[3,7,8,6]
x.remove(max(x))
print(max(x))

#output is 7

Answer 2

If your list is sorted, you don't have to iterate over all element to find the nth-max...

if increasing order mx2 = list[-2]
if decreasing order mx2 = list[1]

... until you've only uniques elements in the list.
If values can be repeated in the list, you need to iterate only over a list subpart:

def mx2(list,inc=True):
i = len(list)-1 if inc else 0
inc = -1 if inc else 1
M = list[i]
try:
while list[i]==M: i += inc
except Exception:
return None
return list[i]

Answer 3

x = list(set([1, 4, 2, 4, 6]))
print(x[-2])

hehe

Answer 4

>>> a = [1,2,4,5,6,72,1,3]
>>> sorted(a)[-2:-1]#start 2 position from left, stop in position from end
[6]#returns array
>>> sorted(a)[-2:-1][0]#pick first element
6
>>>

Answer 5

v0ltr0n no needs to slice before accessing the targeted value...

Francis Sullano using a set imply implicitly to iterate over the whole list (wich could be time expensive for large list and/or numerous call) ;)

Answer 6

mylist = [1, 1, 2, 2, 3, 3, 10, 10, 4, 4, 8, 8, 6, 6, 7, 7, 5, 5, 9, 9]
print(sorted(set(mylist))[-2])