How do I compare 2D lists for equality in Python?

Question

Given two lists:

a = [[1,2],[3,4]]
b = [[1,2],[3,4]]

How would I write compare such that:

compare(a,b) => t         


        

Answer 1

Simple:

def compare(a, b): return a == b

Another way is using lambda to create an anonymous function:

compare = lambda a, b: a == b

Answer 2

Do you want this:

>>> a = [[1,2],[3,4]]
>>> b = [[1,2],[3,4]]
>>> a == b
True

Note: == not useful when List are unordered e.g (notice order in a, and in b)

>>> a = [[3,4],[1,2]]
>>> b = [[1,2],[3,4]]
>>> a == b
False

See this question for further reference: How to compare a list of lists/sets in python?

Edit: Thanks to @dr jimbob

If you want to compare after sorting you can use sorted(a)==sorted(b).
But again a point, if c = [[4,3], [2,1]] then sorted(c) == sorted(a) == False because, sorted(c) being different [[2,1],[4,3]] (not in-depth sort)

_{for this you have to use techniques from linked answer. Since I am learning Python too :)}