Data Structures or Derived data Types in Python:

Storing multiple values of same or different types under a single name. They are collection of data.

List
Tuple
String
Dictionary
Set
In this notebook, we’ll discuss indepth on Sets

Sets:

Sets are unordered collection of unique data. Enclosed by Curly braces {}

set: {10, 20.2, 30.0}

Each value in the set is called a element
Since set is unordered collection, it cannot be indexed. The elements are randomly stored.

Defining a set:

set() method

Syntax:

set(iterable = None)

iterable: any data structures listed above

By default the {} map to a dictionary. So empty curly braces cannot be used.

IN [2]

l = [10, 20, 30]
s = set(l)
s

IN [5]

s = {10, 20, 30, 10, 30}
s

Getting set as input:

s1 = set(input())  
s2 = set(input().split())

Methods or Functions in sets:

There are various methods or functions that are used to work on sets.
1. add
2. update
3. discard
4. pop
5. clear
6. len
7. issubset
8. issuperset
9. union
10. intersection
11. intersection_update
12. difference
13. symmetric_difference
14. copy
15. isdisjoint
16. max
17. min
18. enumerate 19. sum 20. sorted

1. add:

Adds an element to the end of the set.

Syntax: set.add(element)

IN [6]

set1 = {10, 20, 30}
set1.add(40)
set1

2. update:

Adds elements in another set to given set

Syntax: set.update(set)

IN [8]

set1 = {10, 20, 30}
set2 = {10, 25, 40}
set1.update(set2)
set1

3. discard:

Discards the given element in the set.

Syntax: set.discard(element)

IN [9]

set1 = {10, 20, 30}
set1.discard(20)
set1

4. pop:

Removes and returns a random element from set.

Syntax: set.pop()

IN [12]

set1 = {10, 20, 30}
set1.pop()

5. clear:

Empties the set.

Syntax: set.clear()

IN [13]

set1 = {10, 20, 30}
set1.clear()
set1

6. len

Returns the length of the set

Syntax: len(set)

7. issubset:

Checks if a set subset of another.

Syntax: set.issubset(set)
Or set1 <= set2

IN [14]

set1 = {10, 20, 30}
set2 = {10, 20}
set2.issubset(set1)

8. issuperset:

Checks if the set superset of another.

Syntax: set.issuperset(set)
Or set1 >= set2

IN [15]

set1 = {10, 20, 30}
set2 = {10, 20, 30, 35}
set2.issuperset(set1) # set1.issubset(set2)

9. union:

Returns the union of 2 sets

Syntax: set.union(set)
Or set1|set2

IN [16]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1.union(set2)

IN [18]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1|set2

10. intersection:

Returns the intersection of 2 sets

Syntax: set.intersection(set2)
Or set1 & set2

IN [17]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1.intersection(set2)

IN [22]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1 & set2

11. intersection_update:

Updates the set with intersection of given set.

Syntax: set.intersection_update(set)
Or set1 &= set2

IN [24]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1.intersection_update(set2)
set1

IN [25]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1 &= set2
set1

12. difference:

Returns the set difference of given set

Syntax: set1-set2
Or set1 - set2

IN [26]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1.difference(set2)

13. Symmetric Difference:

Returns the symmetric difference of two sets.

Syntax: set.symmetric_difference(set) Or set1 ^ set2

IN [27]

set1 = {10, 20, 30}
set2 = {12, 22, 30}
set1.symmetric_difference(set2)

14. copy:

Copies a set

Syntax: set.copy()

IN [28]

set1 = {10, 20, 30}
set2 = set1.copy()
set2

15. isdisjoint:

Checks if the given sets are mutually exclusive.

Syntax: set.isdisjoint(set)

IN [29]

set1 = {10, 20, 30}
set2 = {1, 22, -37}
set1.isdisjoint(set2)

IN [1]

l = [10, -10, 20, -30, 40]
sum(l)

16. max:

Returns the maximum value in the set.

Syntax: max(set, key = None)

IN [35]

l = {10, 15, 50, 21, -7}
max(l)

IN [36]

l = {10, 15, 50, 21, -7, 7}
max(l, key = lambda x: x % 5) # Maximum reminder when divided by 5

17. min:

Returns minimum value in the iterable

Syntax: min(iterable, key = None)

IN [37]

l = {10, 15, 50, 21, -7}
min(l)

18. enumerate:

Returns the enumerate object for given set. An enumerate object is an iterable which contains ordered pair of the form (index, value)

Syntax: enumerate(iterable, start = 0)

IN [39]

l = {10, 20, 'Hello', 'a', -1}
list(enumerate(l))

19. sum:

returns the sum elements in the set.

Syntax: sum(set, start = 0)

20. sorted:

It is a function used to sort.

Syntax: sorted(iterable, key = None, reverse = False)

Printing the elements in a set:

Using loops
Using Variable length argument ( * )

1. Looping:

Use for loop to access element.

2. Using * :

Using * will convert the elements of into arguements of print method

IN [30]

set1 = {10, 20, 30}
for i in set1:
    print(i)

stdout

10
20
30

IN [31]

set1 = {10, 20, 30}
print(*set1)

stdout

10 20 30

Comprehensions:

IN [32]

set1 = set(i+1 for i in range(0, 10))
set1

all and any:

any checks if any of the element in an iterable is true.

all checks if all the element on an iterable is True

IN [33]

l = [10, 20, 30, 0]
print(any(l))
print(all(l))

stdout

True
False

IN [34]

set1 = {10, 20, 30, -1}
print(any(set1))
print(all(set1))

stdout

True
True