Q: Python - How to find an item exists in a list (or sublist)? For example 
my_list = [1, 2, 3, 4, [5, 6], [7, 8]]

I want to find if 7 is in my_list.? The answer should be True, because it is part of the last sublist. Any ideas?

A: If mylist was a list of only lists you could use itertools.chain.from_iterable()
import itertools
mylist = [[1,2,3,4],[5,6],[7,8]]
merged = list(itertools.chain.from_iterable(mylist))
7 in merged

Since we have a list of ints mixed with lists, we define a custom filter.  This could also be done in a single list comprehension, but I can't figure that out right now.
mylist = [1,2,3,4,[5,6],[7,8]]
merged = []
map(lambda l: merged.extend(l) if isinstance(l, list) else merged.append(l), [i for i in mylist])
7 in merged

You could also use the deprecated compiler.ast.flatten function:
from compiler.ast import flatten
merged = flatten(mylist)

