Second Largest

second_largest.py

def second_largest(list_of_numbers):
    return sorted(set(list_of_numbers))[-2]
    
    
def second_largest_two(list_of_numbers):
    x = None
    for i in list_of_numbers:
        if x is None or i > x:
            x, y = i, x
    return y
    
def second_largest_three(list_of_numbers):
    x = None
    for i in list_of_numbers:
        if x is None or i > x:
            y = x
            x = i
    return y


Thought Process:
    
>>> def second_largest_two(list_of_numbers):
    x, y = list_of_numbers.pop(), list_of_numbers.pop()
    if x > y: x, y = y, x
    for i in list_of_numbers:
        if i > y: x, y = y, i
    return x

>>> second_largest_two([1,2,3,3,4,4,5,6,6,7,7])
7
>>> def second_largest_two(list_of_numbers):
    x, y = list_of_numbers.pop(), list_of_numbers.pop()
    if x > y: x, y = y, x
    for i in list_of_numbers:
        if i > y: x, y = y, i
        elif x < i < y: x = i
    return x

>>> def second_largest_two(list_of_numbers):
    x, y = list_of_numbers.pop(), list_of_numbers.pop()
    if x > y: x, y = y, x
    for i in list_of_numbers:
        if i > y: x, y = y, i
        elif x < i < y: x = i
    return x

>>> second_largest_two([1,2,3,3,4,4,5,6,6,7,7])
7
>>> def second_largest_two(list_of_numbers):
    x, y = None
    for i in list_of_numbers:
        if x is None or i > x:
            x, y = i, x
    return x

>>> second_largest_two([1,2,3,3,4,4,5,6,6,7,7])
Traceback (most recent call last):
  File "<pyshell#10>", line 1, in <module>
    second_largest_two([1,2,3,3,4,4,5,6,6,7,7])
  File "<pyshell#9>", line 2, in second_largest_two
    x, y = None
TypeError: 'NoneType' object is not iterable
>>> def second_largest_two(list_of_numbers):
    x = None
    for i in list_of_numbers:
        if x is None or i > x:
            x, y = i, x
    return x

>>> second_largest_two([1,2,3,3,4,4,5,6,6,7,7])
7
>>> def second_largest_two(list_of_numbers):
    x = None
    for i in list_of_numbers:
        if x is None or i > x:
            x, y = i, x
    return y

>>> second_largest_two([1,2,3,3,4,4,5,6,6,7,7])
6
>>>