Subsets in Python programming language

Subsets are an essential part of set theory and have vast applications in computing and data science. In Python, subsets are essentially a set of smaller collections of elements derived from a larger collection, where each element in the subset is selected based on a certain criterion. You might need to extract specific subsets of data from large datasets, or maybe you are simply curious about how subsets work in Python. 

What is a Subset :

• If all the elements of  set_1  are also present in  set_2  then  set_1  is called a subset of  set_2 .
• If  set_1  is not equal to  set_2  then  set_1  is called a proper subset of  set_2 .
• A set is also a subset of itself.
• In Python we can find if one set is a subset of another by using the : 
  • issubset() method
  • subset operator '<='
  • proper subset operator '<'

using issubset() method :

• This built-in method  issubset()  can be used to check if a set is a subset of another or not.
• The basic syntax of using the  issubset()  method is :  bool_value = set_1.issubset(set_2) 
• The  issubset()  method returns a boolean value :
  • True  set_1  is a subset of  set_2  
  • False if  set_1  is not a subset of  set_2  
• Code Sample : 

set_1 = {1, 2, 3}
set_2 = {1, 2, 3, 4, 5, 6, 7}
val = set_1.issubset(set_2)

print(f"Value of set_1 = {set_1}")
print(f"Value of set_2 = {set_2}")
print(f"set_1 is subset of set_2 = {val}")

# Output
# Value of set_1 = {1, 2, 3}
# Value of set_2 = {1, 2, 3, 4, 5, 6, 7}
# set_1 is subset of set_2 = True

using the subset operator '<=' :

• The subset operator can be used to check if a set is a subset of another or not.
• The basic syntax of using subset operator is :  set_1 <= set_2 
• The subset operator returns a boolean value :
  • True if  set_1  is a subset of  set_2  
  • False if  set_1  is not a subset of  set_2  
• Code Sample : 

set_1 = {1, 2, 3}
set_2 = {1, 2, 3, 4, 5, 6, 7}
val = set_1 <= set_2

print(f"Value of set_1 = {set_1}")
print(f"Value of set_2 = {set_2}")
print(f"set_1 is subset of set_2 = {val}")

# Output
# Value of set_1 = {1, 2, 3}
# Value of set_2 = {1, 2, 3, 4, 5, 6, 7}
# set_1 is subset of set_2 = True

using the proper subset operator '<' :

• The proper subset operator can be used to check if a set is a proper subset of another or not.
• The basic syntax of using proper subset operator is :  set_1 < set_2 
• The proper subset operator returns a boolean value :
  • True if  set_1  is a proper subset of  set_2  
  • False if  set_1  is not a proper subset of  set_2  
• Code Sample : 

set_1 = {1, 2, 3}
set_2 = {1, 2, 3, 4, 5, 6, 7}
val = set_1 < set_2

print(f"Value of set_1 = {set_1}")
print(f"Value of set_2 = {set_2}")
print(f"set_1 is proper subset of set_2 = {val}")

# Output
# Value of set_1 = {1, 2, 3}
# Value of set_2 = {1, 2, 3, 4, 5, 6, 7}
# set_1 is proper subset of set_2 = True