Sets and its Methods in Python

By Susmitha

Hey Guys,
In this python tutorial, you are going to learn about Sets, it i.e definition, creation and its methods.
In Python Set is a data structure is equivalent to sets in mathematics.

Python has a few methods that set objects can all to perform frequency occurring task. All those methods are discussed here.

Sets and its Methods

A set is a collection which is unordered and unindexed.

You can define a set simply just by naming all of its elements inside brackets. The only exception is the empty set, that can be created by using the method set(). If set(..) has a list, a string or a tuple as a parameter, it will return a set composed of its elements.

 A set cannot have mutable elements like a list, set or dictionary, as its elements.

CREATION OF SET

In Python, sets are written with curly brackets[{}] separated by commas.

x={"Mon","Tue","Wed","Thu","Fri","Sat","Sun"}

z={"25","30","35","40"}

w={"odd","even","prime"}

print(x)

print(z)

print(w)

OUTPUT:

{'Sat', 'Fri', 'Tue', 'Sun', 'Wed', 'Thu', 'Mon'}
{'40', '30', '35', '25'}
{'prime', 'even', 'odd'}

Python Set Methods

Here all methods of set objects and built-in functions are listed that can take set as a parameter and perform some task.

Python Set remove() : Removes Element from the Set
We can remove elements from a set by using the discard() method. Again as we have just discussed that there is no specific index attached to the newly added element in our set.
Syntax:
set.remove(element)

Python Set add() : adds element to a set

We can add elements to a set by using add() method. Remember that, there is no specific index attached.

 Syntax:
set.add(elem)
Python Set copy(): Returns Shallow Copy of a Set

Syntax:

numbers = {1, 2, 3, 4}

new_numbers = numbers
Python Set clear(): remove all elements from a set

Syntax:

set.clear()

Python Set difference() : Returns Difference of Two Sets

Syntax:

A.difference(B)
Python Set difference_update() : Updates Calling Set With Intersection of Sets
Syntax:
A.difference_update(B)
Python Set discard() : Removes an Element from The Set.
Syntax:
s.discard(x)
Python Set intersection() : Returns Intersection of Two or More Sets
Syntax:
A.intersection(*other_sets)
Python Set intersection_update() : Updates Calling Set With Intersection of Sets
Syntax:
A.intersection_update(*other_sets)
Python Set isdisjoint(): Checks Disjoint Sets
Syntax:
set_a.isdisjoint(set_b)
Python Set issubset(): Checks if a Set is Subset of Another Set
Syntax:
A.issubset(B)
Python Set issuperset(): Checks if a Set is Superset of Another Set
Syntax:
A.issuperset(B)
Python Set pop() : Removes an Arbitrary Element
Syntax:
set.pop()
Python Set symmetric_difference() : Returns Symmetric Difference
Syntax:
A.symmetric_difference(B)
Python Set symmetric_difference_update() : Updates Set With Symmetric Difference
Syntax:
A.symmetric_difference_update(B)
Python Set union() : Returns Union of Sets
The union operation on two sets produces a new set containing all the distinct elements from both the sets. In the below example the element “Wed” is present in both the sets.
Syntax:
A.union(*other_sets)
Python Set update() : Add Elements to The Set.
Syntax:
A.update(B)
Python any(): Checks if any Element of an Iterable is True
Syntax:
any(iterable)
Python all(): returns true when all elements in iterable are true
Syntax:
all(iterable)
Python ascii(): Returns String Containing Printable Representation.
Syntax:
ascii(object)
Python bool(): Converts a Value to Boolean.
Syntax:
bool([value])
Python enumerate() : Returns an Enumerate Object
Syntax:
enumerate(iterable, start=0)
Python filter(): constructs iterator from elements which are true
Syntax:
filter(function, iterable)
Python frozenset() : returns immutable frozenset object.
Syntax:
frozenset([iterable])
Python iter() : returns iterator for an object.
Syntax:
iter(object[, sentinel])
Python len()  : Returns Length of an Object.
Syntax:
len(s)
Python max() : returns largest element.
Syntax:
max(iterable, *iterables[,key, default])
max(arg1, arg2, *args[, key])
Python min() : returns smallest element.
Syntax:
min(iterable, *iterables[,key, default])
min(arg1, arg2, *args[, key])
Python map() :  Applies Function and Returns a List.
Syntax:
map(function, iterable, ...)
Python set() : returns a Python set.
Syntax:
set([iterable])
Python sorted() : returns sorted list from a given iterable.
Syntax:
sorted(iterable[, key][, reverse])
Python sum() : Add items of an Iterable.
Syntax:
sum(iterable, start)
Python zip() : Returns an Iterator of Tuples.

Syntax:

zip(*iterables)
 EXAMPLE PROGRAM
x={"Mon","Tue","Wed","Thu","Fri","Sat","Sun"}

y={"Jan","Feb","Mar","Wed"}

x.discard("Sun")     #remove

print(x)

x.add("Sun")    #add

print(x)

z = x|y       #union

print(z)

w = x & y  #intersection

print(w)

a = x- y    #difference

print(a)

b= x <= y      #compare

c = y >= x

print(b)

print(c)

OUTPUT:

{'Tue', 'Sat', 'Wed', 'Mon', 'Fri', 'Thu'}
{'Tue', 'Sat', 'Wed', 'Mon', 'Fri', 'Thu', 'Sun'}
{'Jan', 'Tue', 'Feb', 'Sat', 'Wed', 'Mon', 'Mar', 'Fri', 'Thu', 'Sun'}
{'Wed'}
{'Tue', 'Sat', 'Mon', 'Fri', 'Thu', 'Sun'}
False
False
Also, read:

 

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