Python set Built-in methods

Python sets have several built-in methods for performing operations on sets. Here, we'll go through some of the most commonly used set methods:

add(element): Adds an element to the set.

my_set = {1, 2, 3}
my_set.add(4)
print(my_set)  # Output: {1, 2, 3, 4}

update(iterable): Adds multiple elements from an iterable (e.g., list, tuple, set) to the set.

my_set = {1, 2, 3}
my_set.update([3, 4, 5])
print(my_set)  # Output: {1, 2, 3, 4, 5}

remove(element): Removes an element from the set. Raises a KeyError if the element is not found.

my_set = {1, 2, 3}
my_set.remove(1)
print(my_set)  # Output: {2, 3}

discard(element): Removes an element from the set if it is present. Does nothing if the element is not found.

my_set = {1, 2, 3}
my_set.discard(1)
print(my_set)  # Output: {2, 3}

pop(): Removes and returns an arbitrary element from the set. Raises a KeyError if the set is empty.

my_set = {1, 2, 3}
print(my_set.pop())  # Output: 1 (or 2, 3; the result is arbitrary)

clear(): Removes all elements from the set.

my_set = {1, 2, 3}
my_set.clear()
print(my_set)  # Output: set()

union(iterable): Returns a new set containing elements from the set and the iterable. You can also use the | operator.

set_a = {1, 2, 3}
set_b = {3, 4, 5}
result = set_a.union(set_b)
print(result)  # Output: {1, 2, 3, 4, 5}

intersection(iterable): Returns a new set containing elements present in both the set and the iterable. You can also use the & operator.

result = set_a.intersection(set_b)
print(result)  # Output: {3}

difference(iterable): Returns a new set containing elements present in the set but not in the iterable. You can also use the - operator.

result = set_a.difference(set_b)
print(result)  # Output: {1, 2}

symmetric_difference(iterable): Returns a new set containing elements present in either the set or the iterable, but not in both. You can also use the ^ operator.

result = set_a.symmetric_difference(set_b)
print(result)  # Output: {1, 2, 4, 5}

issubset(iterable): Returns True if the set is a subset of the specified iterable, otherwise False.

set_c = {1, 2}
print(set_c.issubset(set_a))  # Output: True

Common Set Operations in Python:
- Sets support various operations like union, intersection, difference, and symmetric difference.
```
# Example
set1 = {1, 2, 3}
set2 = {2, 3, 4}
union_set = set1.union(set2)
```
Python set add() Method:
- The add() method adds an element to a set.
```
# Example
my_set = {1, 2, 3}
my_set.add(4)
```
remove() and discard() Methods in Python Sets:
- The remove() method removes a specified element, and discard() removes an element if it exists.
```
# Example
my_set = {1, 2, 3}
my_set.remove(2)    # Removes 2
my_set.discard(3)   # Removes 3
```
union() and intersection() Methods in Python Sets:
- The union() method returns the union of two sets, and intersection() returns their intersection.
```
# Example
set1 = {1, 2, 3}
set2 = {2, 3, 4}
union_set = set1.union(set2)
intersection_set = set1.intersection(set2)
```
difference() and symmetric_difference() in Python Sets:
- The difference() method returns elements present in the first set but not in the second, and symmetric_difference() returns elements in either set, but not both.
```
# Example
set1 = {1, 2, 3}
set2 = {2, 3, 4}
difference_set = set1.difference(set2)
symmetric_difference_set = set1.symmetric_difference(set2)
```
Subset and Superset Methods for Sets in Python:
- Methods like issubset() and issuperset() check if one set is a subset or superset of another.
```
# Example
set1 = {1, 2}
set2 = {1, 2, 3, 4}
is_subset = set1.issubset(set2)    # True
is_superset = set2.issuperset(set1)    # True
```

Set Comprehension vs Set Methods in Python:

Set comprehensions and set methods both offer ways to perform set operations, with comprehensions providing a concise and expressive syntax.

# Example with set comprehension
set1 = {x for x in range(1, 6)}
set2 = {x for x in range(4, 9)}

# Example with set methods
union_set = set1.union(set2)
intersection_set = set1.intersection(set2)