1.append():
The append() method is used to append a value at the end of an existing list. The value to be appended is passed as an argument.

arr = []
arr.append(1)
print(arr) #[1]

2.insert():
The insert() method is used to add an element to a list at the specified position. All the elements from the specified position will be shifted to the right. If the given position is out of range, the element will be appended at the end.

print(arr) #[1]
arr.insert(0, 10)
print(arr) #[10, 1]

3.extend():
The extend() method takes a list of values as an argument and adds all the values to the existing list.

print(arr) #[10, 1]
arr.extend([2, 3, 4])
print(arr) #[10, 1, 2, 3, 4]

4.remove():
The remove() method removes the given element from the list. If there are duplicate elements, the first occurrence will be removed, and if the given element is not in the list, exception will be raised.

print(arr) [10, 1, 2, 3, 4]
arr.remove(10)
print(arr) [1, 2, 3, 4]
arr.remove(12) #ValueError: list.remove(x): x not in list

5.pop():
The pop() method is used to remove an element at a specified index from the list. If the index position is not given, last element will be removed.

print(arr) #[1, 2, 3, 4]
arr.pop(2)
print(arr) #[1, 2, 4]
arr.pop()
print(arr) #[1, 2]
arr.pop(4) #IndexError: pop index out of range

6.index():
The index() method takes a value as an argument and returns the index of first occurrence position of that value. If the value is not in the list, an exception will be raised.

print(arr) #[1, 2]
print(arr.index(2)) #1
print(arr.index(3)) #ValueError: list.index(x): x not in list

7.count():
The count() method takes a value as an argument, searches the value in the list and returns the number of times the value has repeated in the list.

print(arr) #[1, 2]
print(arr.count(2)) #1
arr.extend([2, 3, 4, 5])
print(arr.count(2)) #2

8.reverse():
This method reverses the list and returns the reversed list as an output.

print(arr) #[1, 2, 2, 3, 4, 5]
arr.reverse()
print(arr) #[5, 4, 3, 2, 2, 1]

9.sort():
This method sorts the list list in-place in ascending or descending order. By default, this method sorts the list in ascending order. To sort the list in the descending order we should set reverse to True in the argument.

print(arr) #[5, 4, 3, 2, 2, 1]
arr.sort()
print(arr) #[1, 2, 2, 3, 4, 5]
arr.sort(reverse=True)
print(arr) #[5, 4, 3, 2, 2, 1]

10.copy():
This methods returns a copy of the list.

print(arr) #[5, 4, 3, 2, 2, 1]
arr2 = arr.copy()
print(arr2) #[5, 4, 3, 2, 2, 1]

11.clear():
This method is used to remove all the values inside a list.

print(arr) #[5, 4, 3, 2, 2, 1]
arr.clear()
print(arr) #[]

References:

• Python List/Array Methods, W3Schools.
• Python List Methods, Programiz.