my_set = set() # Use this to declare an empty set in python

my_set = {"apple", "orange"} # Use this to declare a set in python

# You can't create a set like this in Python

my_set = {} # ---- This is a Dictionary/Hashmap

​

# To create a empty set you have to use the built in method:

my_set = set() # Correct!

​

​

set_example = {1,3,2,5,3,6}

print(set_example)

​

# OUTPUT

# {1,3,2,5,6} ---- Sets do not contain duplicates and are unordered

​

# A set contains unique elements of which the order is not important

s = set()

s.add(1)

s.add(2)

s.remove(1)

print(s)

# Can also be created from a list (or some other data structures)

num_list = [1,2,3]

set_from_list = set(num_list)

>>> A = {0, 2, 4, 6, 8};

>>> B = {1, 2, 3, 4, 5};

​

>>> print("Union :", A | B)  

Union : {0, 1, 2, 3, 4, 5, 6, 8}

​

>>> print("Intersection :", A & B)

Intersection : {2, 4}

​

>>> print("Difference :", A - B)

Difference : {0, 8, 6}

​

# elements not present both sets

>>> print("Symmetric difference :", A ^ B)   

Symmetric difference : {0, 1, 3, 5, 6, 8}

​

empty_set = set()

​

basket = {'apple', 'orange', 'apple', 'pear', 'orange', 'banana'}

​

# sets do not contain duplicates

print(basket)                      

# output {'orange', 'banana', 'pear', 'apple'}

​

# check if orange is in basket set

print('orange' in basket)

# output true

​

# convert a string to a set of letters - sets contains no duplicates

set_a = set('abcd')

set_b = set('bcde')

​

# the operations below returns new sets

# print letters in set_a but not in set_b - difference

print(set_a - set_b)

# output {'a'}

​

# print set letters that is in either set a or b - union

print(set_a | set_b)

# output {'a', 'c', 'e', 'b', 'd'}

​

# print letters that are in both set_a and set_b - intersection

print(set_a & set_b)

# output {'c', 'd', 'b'}

​

# print letters that are in set_a and set_b when the letters are found in a set but no the other set - symmetric_difference()

print(set_a ^ set_b)

# output {'a', 'e'}

​

myNewSet = set()

​

myNewSet.add("what have you done")

myNewSet.add("to earn your place")

myNewSet.add("in this crowded world?")

​

​

"what have you done" in myNewSet        # ->    true

myNewSet.remove("to earn your place")

# ->     myNewSet = {"what have you done", "in this crowded world?"}

set_example = {1, 2, 3, 4, 5, 5, 5}

​

print(set_example)

​

# OUTPUT

# {1, 2, 3, 4, 5} ----- Does not print repetitions

set_of_base10_numbers = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0}

set_of_base2_numbers = {1, 0}

​

intersection = set_of_base10_numbers.intersection(set_of_base2_numbers)

union = set_of_base10_numbers.union(set_of_base2_numbers)

​

'''

intersection: {0, 1}:

    if the number is contained in both sets it becomes part of the intersection

union: {0, 1, 2, 3, 4, 5, 6, 7, 8, 9}:

    if the number exists in at lease one of the sets it becomes part of the union

'''

# Creating an empty set

b = set()

print(type(b))

​

## Adding values to an empty set

b.add(4)

b.add(4)

b.add(5)

b.add(5) # Adding a value repeatedly does not changes a set

b.add((4, 5, 6))

​

## Accessing Elements

# b.add({4:5}) # Cannot add list or dictionary to sets

print(b)

​

## Length of the Set

print(len(b)) # Prints the length of this set

​

## Removal of an Item

b.remove(5) # Removes 5 fromt set b

# b.remove(15) # throws an error while trying to remove 15 (which is not present in the set)

print(b)

​

print(b.pop())

print(b)

A_Set = {1, 2, "hi", "test"}

​

for i in A_Set: #Loops through the set. You only get the value not the index

  print(i) #Prints the current value

# Python also has sets which you can use

# Keep in mind that sets cannot have duplicate of the same value

# This can be useful for removing doubles in a list

​

mySet = {1, 2, 2, 3, 4, 5, 10, 10, 15}

print(mySet) # {1, 2, 3, 4, 5, 10, 15}

​

# You can also create a set with 'set([list elements])'

​

myList = ['apples', 'bananas', 'oranges', 'grapes']

myList.append('apples')

myList.append('oranges')

print(myList) # ['apples', 'bananas', 'oranges', 'grapes', 'apples', 'oranges']

​

myNewSet = set(myList)

print(myNewSet) # {'apples', 'bananas', 'oranges', 'grapes'}