[]: Used to define mutable data types - lists, list comprehensions and for indexing/lookup/slicing.
(): Define tuples, order of operations, generator expressions, function calls and other syntax.
{}: The two hash table types - dictionaries and sets.
slicing:
https://docs.scipy.org/doc/numpy/reference/arrays.indexing.html
ex·clu·sive OR (xor)
a Boolean operator working on two variables that has the value of one if one but not both of the variables has a value of one.
