How can an array of data be declared and initialized in Python?

In Python, a data array is usually represented as a list. It can be declared and initialized in several ways:

# Empty list
arr = []

# List with elements
arr = [1, 2, 3, 4, 5]

# List with elements of different types
arr = [1, 'string', 3.14, True]

# Creating a list using a generator
arr = [x * 2 for x in range(5)]  # [0, 2, 4, 6, 8]

If you need a structure with homogeneous types and a fixed size, you can use the array module:

import array
arr = array.array('i', [1, 2, 3, 4])  # array of integers

For scientific computations, numpy arrays are often used:

import numpy as np
arr = np.array([1, 2, 3, 4])