Introduction:

• Python provides a set of built-in methods that you can use to manipulate lists (arrays). These methods make it easy to add, remove, and modify elements in your arrays.

Common Array Methods:

1. append()

   • Adds an element at the end of the list.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     cars.append("Honda")
     print(cars) 

     •  Output: ['Ford', 'Volvo', 'BMW', 'Honda'] 

       Code Lab
2. clear()

   • Removes all elements from the list.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     cars.clear()
     print(cars)  

     •  Output: [] 

       Code Lab
3. copy()

   • Returns a copy of the list.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     new_cars = cars.copy()
     print(new_cars)  

     •  Output: ['Ford', 'Volvo', 'BMW'] 

       Code Lab
4. count()

   • Returns the number of elements with the specified value.

     

     python

     fruits = ["apple", "banana", "cherry", "apple"]
     print(fruits.count("apple"))  

     •  Output: 2 

       Code Lab
5. extend()

   • Adds the elements of a list (or any iterable) to the end of the current list.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     more_cars = ["Honda", "Toyota"]
     cars.extend(more_cars)
     print(cars)  

     •  Output: ['Ford', 'Volvo', 'BMW', 'Honda', 'Toyota']

       Code Lab
6. index()

   • Returns the index of the first element with the specified value.

     

     python

     fruits = ["apple", "banana", "cherry"]
     print(fruits.index("banana"))  

     •  Output: 1

       Code Lab
7. insert()

   • Adds an element at the specified position.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     cars.insert(1, "Honda")
     print(cars)  

     •  Output: ['Ford', 'Honda', 'Volvo', 'BMW'] 

       Code Lab
8. pop()

   • Removes the element at the specified position.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     cars.pop(1)
     print(cars)   

     •  Output: ['Ford', 'BMW'] 

       Code Lab
9. remove()

   • Removes the first item with the specified value.

     

     python

     cars = ["Ford", "Volvo", "BMW"]
     cars.remove("Volvo")
     print(cars)   

     •  Output: ['Ford', 'BMW']

       Code Lab
10. reverse()

    • Reverses the order of the list.

      

      python

      cars = ["Ford", "Volvo", "BMW"]
      cars.reverse()
      print(cars)  

      •  Output: ['BMW', 'Volvo', 'Ford'] 

        Code Lab
11. sort()

    • Sorts the list.

      

      python

      cars = ["Ford", "Volvo", "BMW"]
      cars.sort()
      print(cars)  

      •  Output: ['BMW', 'Ford', 'Volvo']

        Code Lab

Exercises:

1. Add and Remove Elements:

   • Create a list of numbers and add a new number at the end, then remove the first number.

     

     python

     numbers = [1, 2, 3, 4]
     numbers.append(5)
     numbers.remove(1)
     print(numbers)    

     •  Output: [2, 3, 4, 5]

       Code Lab
2. Copy and Clear List:

   • Copy a list of fruits and then clear the original list.

     

     python

     fruits = ["apple", "banana", "cherry"]
     new_fruits = fruits.copy()
     fruits.clear()
     print(new_fruits)  
     print(fruits)      

     •  Output: ['apple', 'banana', 'cherry']

     • Output:  [] 

       Code Lab

Summary:

• In this tutorial, we learned about various built-in methods to manipulate arrays in Python. These methods are essential for managing and processing data stored in arrays. Practice using these methods to get comfortable with array manipulation in Python!