• These include the following:
  • Lists
    • my_list = [1,2,3,4]
    • print(my_list) [1,2,3,4]
  • Can also use strings:
    • my_list = ['list', 'of', 'strings']
  • Can have list of strings, integers, booleans, a list within a list etc:
    • `my_list = [‘1’, ‘list’, ‘False’, []]
  • List of lists:
    • my_list = [[1,2,3],[False, True],[]]
  • There is a function that Lists use called length.
    • len(my_list and we’re using the list just above.
      • The output is 3.
  • Sets
    • Identical to a list, however all elements inside it have to be unique.
    • Can define a set with curl brackets such as my_set = {1,2,3,4,5}.
      • Then print it with: print(my_set) displays: {1,2,3,4,5}
    • To find the type used, you can run type(my_set). It will then output: set.
    • Can use the length function as well, in this case len(my_set) = 5.
    • Another example is:
    • my_set = {1,1,2,2}
    • len(my_set) 2
      • The output is 2, because every element in the set needs to be unique.
    • Then if you print with print(my_set), can only see the following two elements: {1, 2}
  • Order of elements in a List is very important.
  • For example [1,2] == [2,1], which is False
  • However for a Set, the following is True.
    • {1,2} == {2,1} = True
  • Tuples
    • Declared in parenthesis, such as:
    • my_tuple = (1,2,3)
    • Very similar to Lists.
    • len(my_tuple) = 3.
    • The order of Tuples is also important:
      • (1,2) == (2,1) = False.
    • The difference with Tuples, is that things cannot be appended or added to them.
    • For example, my_list.append(4)
    • print(my_list) (from before), adds the number 4 to the list.
      • If however you do my_tuple.append(4), this is not allowed. You are not able to modify tuples.
        • One a tuple is declared, you can’t add or change any of its values.
    • Why use Tuples?
      • They are memory efficient.
        • Python will usually pre-allocate a chunk of memory to a list.
          • However with Tuples these use only the exact amount of memory it needs.
          • Useful for storing smaller values such as x/y coordinates.
            • Much more memory efficient than lists.
  • Dictionaries my_dictionary = { 'apple': 'A red fruit', 'bear': 'A scary animal' }
  • Key Value pairs are placed inside of dictionaries.
  • If you then run my_dictionary['apple'] outputs 'A red fruit'
    • If provides you the definition/value of what you get back from the key.
  • The keys have to be unique. For example: my_dictionary = { 'apple': 'A red fruit', 'bear': 'A scary animal' 'apple': 'Sometimes a green fruit' }
  • Then run my_dictionary['apple'], you get 'Sometimes a green fruit'
  • Sets and Dictionaries
    • Both are defined with curl brackets.
    • Sets have unique values, dictionaries have unique keys.
    • The order doesn’t matter.

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