notes

//  = int val in division 
/ = float val in division


# aama c ni jem define n hoy aapde capital ma lakhi to 

e constant j ganay , 

EX:
PAI =  3.14 



imoprt math karine

pai.math kari to e direct pai ni val j aape 

remove() Method

    Removes the first occurrence of a specific value from the list.
    Raises a ValueError if the value is not found.

arr = [10, 20, 30, 40, 30]
arr.remove(30)  # Removes the first 30 from the list
print(arr)  # Output: [10, 20, 40, 30]

2. pop() Method

    Removes an element at a specified index.
    If no index is provided, it removes the last 
element by default.
    Returns the removed element.

arr = [10, 20, 30, 40]
removed = arr.pop(2)  # Removes the element at index 2 (30)
print(arr)  # Output: [10, 20, 40]


print(removed)  # Output: 30

arr = [10, 20, 30, 40]
arr.pop()  # Removes the last element (40)
print(arr)  # Output: [10, 20, 30]


3. del Statement

    Deletes an element at a specified index or slices of a list.

arr = [10, 20, 30, 40]
del arr[1]  # Removes the element at index 1 (20)
print(arr)  # Output: [10, 30, 40]



arr = [10, 20, 30, 40, 50]
del arr[1:3]  # Removes elements at indices 1 and 2 (20, 30)
print(arr)  # Output: [10, 40, 50]

Using List Comprehension

    Creates a new list by excluding specific elements without modifying the original list.

arr = [10, 20, 30, 40, 30]
arr = [x for x in arr if x != 30]  # Removes all occurrences of 30
print(arr)  # Output: [10, 20, 40]




5. clear() Method

    Removes all elements from the list, leaving it empty.




arr = [10, 20, 30, 40]
arr.clear()
print(arr)  # Output: []





seen = set() is used to create an empty set in Python.
A set is a built-in data structure that holds unique 
elements and does not allow duplicates. 
It is particularly useful for keeping track
of items that have already been encountered or processed.

What Does seen = set() Do?

    Initializes an Empty Set:
        set() creates an empty set,
which can later store elements.
For example:

seen = set()


Stores Unique Items Only:

    Sets automatically remove duplicates. 
If you add the same element multiple times, 
it will appear only once.

Efficient Membership Check:

    You can check if an element is already in
the set using the in keyword,
which is faster in a set compared to a list.


end=" " in print():

    By using end=" ", the elements of 
a row are printed on the same
line with a space separating them,
instead of the default newline.

print(line.strip())   # Strip removes trailing newline or spaces