In Python, a list is a built-in data structure that holds an ordered, mutable collection of items. Python provides several in-built methods for list manipulation. Here's a complete and organized explanation of all commonly used in-built list methods:

🔹 List In-Built Methods in Python

✅ 1. append()

• Purpose: Adds an element at the end of the list.

• Syntax: list.append(element)

• Example:

  fruits = ['apple', 'banana']
  fruits.append('cherry')
  print(fruits)  # ['apple', 'banana', 'cherry']
  

✅ 2. extend()

• Purpose: Adds elements from another iterable (list, tuple, etc.) to the end.

• Syntax: list.extend(iterable)

• Example:

  a = [1, 2]
  b = [3, 4]
  a.extend(b)
  print(a)  # [1, 2, 3, 4]
  

✅ 3. insert()

• Purpose: Inserts an element at a specified index.

• Syntax: list.insert(index, element)

• Example:

  nums = [1, 3, 4]
  nums.insert(1, 2)
  print(nums)  # [1, 2, 3, 4]
  

✅ 4. remove()

• Purpose: Removes the first occurrence of a value.

• Syntax: list.remove(element)

• Example:

  items = [1, 2, 3, 2]
  items.remove(2)
  print(items)  # [1, 3, 2]
  

✅ 5. pop()

• Purpose: Removes and returns the element at a given index (default is last).

• Syntax: list.pop([index])

• Example:

  items = ['a', 'b', 'c']
  last = items.pop()
  print(last)   # 'c'
  

✅ 6. clear()

• Purpose: Removes all items from the list.

• Syntax: list.clear()

• Example:

  data = [1, 2, 3]
  data.clear()
  print(data)  # []
  

✅ 7. index()

• Purpose: Returns the first index of a value.

• Syntax: list.index(value[, start[, end]])

• Example:

  names = ['Alice', 'Bob', 'Alice']
  print(names.index('Alice'))  # 0
  

✅ 8. count()

• Purpose: Returns the number of times a value appears.

• Syntax: list.count(value)

• Example:

  a = [1, 2, 2, 3]
  print(a.count(2))  # 2
  

✅ 9. sort()

• Purpose: Sorts the list in ascending order (or custom).

• Syntax: list.sort(reverse=False, key=None)

• Example:

  nums = [4, 1, 3]
  nums.sort()
  print(nums)  # [1, 3, 4]
  

✅ 10. reverse()

• Purpose: Reverses the order of elements in the list.

• Syntax: list.reverse()

• Example:

  nums = [1, 2, 3]
  nums.reverse()
  print(nums)  # [3, 2, 1]
  

✅ 11. copy()

• Purpose: Returns a shallow copy of the list.

• Syntax: list.copy()

• Example:

  a = [1, 2]
  b = a.copy()
  print(b)  # [1, 2]
  

🔁 Summary Table