Odtnhj

I am doing code academy and came across this question:

Create a function called middle_element that has one parameter named
lst.

If there are an odd number of elements in lst, the function should
return the middle element. If there are an even number of elements,
the function should return the average of the middle two elements.

This was my code:

def middle_element(lst):
 if (len(lst)%2) = 0:
 return lst[len(lst)/2]
else:
 firstel= lst[len(lst/2-1)]
 secel= lst[len(lst/2+1)]
 avg = firstel+secel/2
 return avg

Unable to compile due to Syntax error

:( Can anyone advise me? Thank you!

Sigh, probably a total beginner. Let's fix the indents first, so your code is looking like this.

def middle_element(lst):
 if (len(lst)%2) = 0:
 return lst[len(lst)/2]
 else:
 firstel= lst[len(lst/2-1)]
 secel= lst[len(lst/2+1)]
 avg = firstel+secel/2
 return avg

Next to fix is the = sign in the comparison. You don't want to assign a variable here, but compare, so you need

def middle_element(lst):
 if (len(lst)%2) == 0:
 return lst[len(lst)/2]
 else:
 firstel= lst[len(lst/2-1)]
 secel= lst[len(lst/2+1)]
 avg = firstel+secel/2
 return avg

However now you are executing the statement return lst[len(lst)/2] when the list has an even number of elements. You want to have this the other way round. This statement should get executed when there are an odd number of elements in the list, so:

def middle_element(lst):
 if (len(lst)%2) == 1:
 return lst[len(lst)/2]
 else:
 firstel= lst[len(lst/2-1)]
 secel= lst[len(lst/2+1)]
 avg = firstel+secel/2
 return avg

As a minor change I would transform

return lst[len(lst)/2]

into

return lst[len(lst)//2]

to prevent problems with python3. Now to the coder in the else-part which is totally wrong too, it should be

firstel= lst[len(lst)//2]
secel= lst[len(lst)//2+1]
avg = (firstel+secel)/2
return avg

Since the len()-function expects a list, not a list divided by something. Furthermore you need braces between (firstel+secel)/2 otherwise you would calculate firstel+(secel/2) which is not the average. So in total:

from __future__ import division

def middle_element(lst):
 if len(lst) % 2 == 1:
 return lst[len(lst) // 2]
 else:
 firstel = lst[len(lst) // 2 - 1]
 secel = lst[len(lst) // 2]
 avg = (firstel + secel) / 2
 return avg