What Is the Data Type of NumPy Object?


Angela Bailey

What Is the Data Type of NumPy Object?

NumPy is a powerful library in Python that provides support for large, multi-dimensional arrays and matrices, along with a collection of mathematical functions to operate on these arrays. When working with NumPy, it’s essential to understand the data types of the objects it handles.

1. NumPy Data Types

NumPy has a rich set of built-in data types that allow you to represent and manipulate different kinds of data efficiently. These data types are represented using objects called “dtype”.

The “dtype” object in NumPy consists of two parts:

  • Type information (integer, float, etc.)
  • Size information (how many bytes does each element take)

A. Numeric Data Types

Numeric data types in NumPy can be categorized as integers and floating-point numbers.

The most commonly used integer dtypes are:

  • int8: Byte (-128 to 127)
  • int16: Integer (-32768 to 32767)
  • int32/u>: Integer (-2147483648 to 2147483647)
  • int64: Integer (-9223372036854775808 to 9223372036854775807)

The most commonly used floating-point dtypes are:

  • float16: Half precision float: sign bit, 5 bits exponent, 10 bits mantissa
  • float32: Single precision float: sign bit, 8 bits exponent, 23 bits mantissa
  • float64: Double precision float: sign bit, 11 bits exponent, 52 bits mantissa

B. Complex Data Types

NumPy also provides complex data types to represent complex numbers. The two commonly used complex dtypes are:

  • complex64: Complex number represented by two 32-bit floats (real and imaginary parts)
  • complex128: Complex number represented by two 64-bit floats (real and imaginary parts)

2. Determining the Data Type of a NumPy Object

To determine the data type of a NumPy object, you can use the dtype attribute.

Let’s consider an example:

import numpy as np

arr = np.array([1, 2, 3])


This code snippet creates a NumPy array with three elements and prints its data type. In this case, it will output:


The output indicates that the data type of the array is “int64”, which means it is a 64-bit integer.

3. Changing the Data Type of a NumPy Object

You can also change the data type of a NumPy object using the astype() function.

Here’s an example:

new_arr = arr.astype(‘float64’)


This code snippet creates a NumPy array, converts it to a “float64” data type using the astype() function, and prints the new data type.

The output will be:


The output confirms that the data type of the new array is now “float64”, indicating that it is a 64-bit floating-point number.

4. Conclusion

In this tutorial, we explored the various data types available in NumPy and learned how to determine and change the data type of a NumPy object. Understanding the data types used in NumPy is crucial for performing efficient computations and ensuring accurate results in your Python programs.

Now that you have a good grasp of NumPy’s data types, you can confidently tackle complex numerical computations with ease!