Python array append: How to Append Item in Python Array

In programming terms, an array is a linear data structure that stores similar kinds of elements. Array data type does not exist in Python. Instead, you can use a Python list or numpy array.

The list is similar to an array in other programming languages. If you look at the list as an array, then to append an item to the array, use the list append() method.

To create an array in Python, use one of the following ways.

  1. Python list
  2. Python array using array module.
  3. Python numpy array

Python array append

To append an item in the array in Python, use the list append() method. The append() method appends an element to the end of the list.

Syntax

list.append(element)

Parameters

The append() function takes an element as a parameter and returns the appended list.

Return Value

The method doesn’t return any value and None.

Example

list = ["Wonder Woman 84", "Suicide Squad", "Tom and Jerry"]
print(list)
print("After appending a new element")
list.append("Friends")
print(list)

Output

['Wonder Woman 84', 'Suicide Squad', 'Tom and Jerry']
After appending a new element
['Wonder Woman 84', 'Suicide Squad', 'Tom and Jerry', 'Friends']

Python array module

We can create an array using the Array module and then apply the append() function to add elements to it. To work with the array module, import the array module.

To initialize an array using the array module in Python, use the array.array() method.

array.array('unicode', elements)

unicode: It represents the type of elements to be occupied by the array. For example, ‘i’ represents integer elements.

To append an item in the array, use the array.append() method.

import array

data = array.array('i', [11, 21])
d2 = 19
data.append(d2)
print(data)

Output

array('i', [11, 21, 19])

The array append() method added an element at the end of the array.

Numpy array append in Python.

Python numpy append() method appends values to the end of an array. A Numpy module can be used to create an array and manipulate the data against various mathematical functions.

We will create two arrays using the np.arange() function and append two arrays.

import numpy as np

k1 = np.arange(4)
print("First array : ", k1)

k2 = np.arange(4, 9)
print("Second array : ", k2)

op = np.append(k1, k2)
print("\nResult after appending k1 and k2: ", op)

Output

First array :  [0 1 2 3]
Second array :  [4 5 6 7 8]

Result after appending k1 and k2:  [0 1 2 3 4 5 6 7 8]

In this example, we got the result of the combined array of k1 and k2.

Conclusion

Numpy array slicing

Numpy array to list

Numpy array shape

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