Python - Arrays

The append() method in Python arrays is used to add elements to the end of the array. Here's an example program demonstrating the use of the append() method:

# Create an array
my_array = [1, 2, 3, 4, 5]

# Display the original array
print("Original Array:", my_array)

# Append a new element to the array
my_array.append(6)

# Display the array after appending
print("Array after Append:", my_array)

Output:

Original Array: [1, 2, 3, 4, 5]
Array after Append: [1, 2, 3, 4, 5, 6]

In this example, the append() method is used to add the element 6 to the end of the array my_array.

The extend() and append() methods in Python arrays are used to add elements, but they differ in their behavior. Let's discuss the difference with examples:

# Using extend() method
arr1 = [1, 2, 3]
arr2 = [4, 5, 6]
arr1.extend(arr2)
print("Using extend():", arr1)

# Using append() method
arr3 = [1, 2, 3]
arr4 = [4, 5, 6]
arr3.append(arr4)
print("Using append():", arr3)

Output:

Using extend(): [1, 2, 3, 4, 5, 6]
Using append(): [1, 2, 3, [4, 5, 6]]

The extend() method adds elements from an iterable (like a list or tuple) to the end of the array, effectively extending it. In contrast, the append() method adds its argument as a single element to the end of the array. If the argument is an iterable, it is added as a nested list within the array.

To remove an element from a specific index in a Python array, you can use the pop() method. Here's an example:

# Create an array
my_array = [1, 2, 3, 4, 5]

# Remove element at index 2
removed_element = my_array.pop(2)

print("Original Array:", my_array)
print("Removed Element:", removed_element)

Output:

Original Array: [1, 2, 4, 5]
Removed Element: 3

The pop() method removes and returns the element at the specified index. In the example, the element at index 2 (value 3) is removed from the array, and the modified array is printed along with the removed element.

Array concatenation in Python involves combining two or more arrays into a single array. This can be done using the + operator or the extend() method. Here's an example:

# Create two arrays
array1 = [1, 2, 3]
array2 = [4, 5, 6]

# Concatenate arrays using the + operator
concatenated_array1 = array1 + array2

# Concatenate arrays using the extend() method
array1.extend(array2)
concatenated_array2 = array1

print("Using + operator:", concatenated_array1)
print("Using extend() method:", concatenated_array2)

Output:

Using + operator: [1, 2, 3, 4, 5, 6]
Using extend() method: [1, 2, 3, 4, 5, 6]

In the example, two arrays (array1 and array2) are concatenated using both the + operator and the extend() method. The resulting concatenated arrays are printed.