PYTHON

python sets

# 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

python sets

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'}

sets in python

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
'''

when to use python sets

"""
The Python sets are highly useful to efficiently remove duplicate values from
a collection like a list and to perform common math operations like unions and
intersections.
"""

python sets

# 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'}

How to Create Sets in Python

nameSet = {"John", "Jane", "Doe"}

print(nameSet)
# {'Jane', 'Doe', 'John'}

Python Sets

# Python program to demonstrate
# Creation of Set in Python
 
# Creating a Set
set1 = set()
print("Initial blank Set: ")
print(set1)
 
# Creating a Set with
# the use of a String
set1 = set("GeeksForGeeks")
print("
Set with the use of String: ")
print(set1)
 
# Creating a Set with
# the use of Constructor
# (Using object to Store String)
String = 'GeeksForGeeks'
set1 = set(String)
print("
Set with the use of an Object: " )
print(set1)
 
# Creating a Set with
# the use of a List
set1 = set(["Geeks", "For", "Geeks"])
print("
Set with the use of List: ")
print(set1)

Python Sets

# Python program to demonstrate
# Creation of Array
 
# importing "array" for array creations
import array as arr
 
# creating an array with integer type
a = arr.array('i', [1, 2, 3])
 
# printing original array
print ("The new created array is : ", end =" ")
for i in range (0, 3):
    print (a[i], end =" ")
print()
 
# creating an array with float type
b = arr.array('d', [2.5, 3.2, 3.3])
 
# printing original array
print ("The new created array is : ", end =" ")
for i in range (0, 3):
    print (b[i], end =" ")