# What Is the Core Data Structure of NumPy?

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Heather Bennett

What Is the Core Data Structure of NumPy?

NumPy is a powerful Python library for numerical computing. It provides efficient data structures and functions for working with large, multi-dimensional arrays and matrices.

At the core of NumPy is its unique data structure, called the NumPy array. In this article, we will explore the key features and benefits of this fundamental data structure.

## The NumPy Array

The NumPy array is a homogeneous, multidimensional container that holds elements of the same type. It can be thought of as a table of elements, where each element is accessed by its index.

This data structure allows for efficient storage and manipulation of numerical data.

Unlike Python lists, which are dynamic and can hold elements of different types, NumPy arrays have a fixed size and are more efficient in terms of both memory usage and execution speed. They are implemented in C, which makes them faster for mathematical computations.

### Creating a NumPy Array

To create a NumPy array, you need to import the `numpy` module first. Then you can use the `numpy.array()` function to create an array from various sources such as lists or tuples.

``````
import numpy as np

# Creating a 1-dimensional array
arr1d = np.array([1, 2, 3, 4, 5])

# Creating a 2-dimensional array
arr2d = np.array([[1, 2], [3, 4], [5, 6]])
``````

### Array Attributes

NumPy arrays have several useful attributes that provide information about their size, shape, and data type. Some of the commonly used attributes include:

• shape: Returns a tuple representing the size of each dimension of the array.
• dtype: Returns the data type of the elements in the array.
• size: Returns the total number of elements in the array.
``````
# Example usage of array attributes
print(arr1d.shape)  # Output: (5,)
print(arr2d.dtype)  # Output: int64
print(arr2d.size)   # Output: 6
``````

### Array Indexing and Slicing

Just like Python lists, NumPy arrays can be accessed and manipulated using indexing and slicing. You can use square brackets along with indices or slices to access specific elements or subarrays.

``````
# Example usage of array indexing and slicing
print(arr1d[0])         # Output: 1
print(arr2d[1, 0])      # Output: 3

subarr = arr1d[1:4]     # Slicing from index 1 to 3 (exclusive)
print(subarr)          # Output: [2, 3, 4]
``````

## Benefits of NumPy Arrays

NumPy arrays offer several advantages over traditional Python lists when it comes to numerical computations:

• Efficiency: NumPy arrays are more memory-efficient and faster compared to lists due to their fixed size and C implementation.
• Broadcasting: NumPy provides powerful broadcasting capabilities, allowing you to perform operations between arrays of different shapes.
• Vectorized operations: NumPy supports vectorized operations, enabling you to apply functions or mathematical operations to the entire array without the need for explicit loops.
• Integration with other libraries: NumPy is widely used as a foundation for other scientific computing libraries such as SciPy and pandas.

In conclusion, the NumPy array is a fundamental data structure in NumPy that provides efficient storage and manipulation of numerical data. Understanding its core features and benefits is essential for anyone working with numerical computations in Python.

Now that you have a good grasp of the core data structure of NumPy, you can start exploring its vast capabilities in scientific computing and data analysis.