Skip to content

Pythoneo

Online How to Python stuff

How to get NumPy array length?

Posted on December 24, 2021March 2, 2023 By Luke K

Here’s an easy way to find the length of a NumPy array.

Numpy array length

Array length

To calculate the length of the array, just use the Numpy size method.

import numpy as np
my_array = np.array([[1,2,3],[4,5,6],
                     [7,8,9],[10,11,12]])
print(f"Length of my array equals: {my_array.size}")

Numpy array length

As an output, you get 12 as the length of the array.

Array shape

Now you know the length, but this information might not be enough for you. Let’s see the shape of the array.

import numpy as np
my_array = np.array([[1,2,3],[4,5,6],
                     [7,8,9],[10,11,12]])
print(f"Shape of my array: {my_array.shape}")

Numpy array shape

The shape of an array is 4 x 3, which is 12 in total. This is the output which gives you more information about the size of an array. You just need to remember that to get the length of an array, you need to multiply the output of the shape method.

See also  How to calculate moving sum and moving average using Numpy Convolve?

Array size

Knowing the shape of the array is only the point of view. You might be interested in what the actual size of the array is from the storage point of view. This is how you get information about how many bytes your array consumes:

import numpy as np
my_array = np.array([[1,2,3],[4,5,6],
                     [7,8,9],[10,11,12]])
print(f"The array is using {my_array.nbytes} bytes.")

numpy bytes nbytes

Thanks to the nbytes method, you know that the array is using 48 bytes.

See also  How to trim an array with Numpy clip?

This is how you get the full picture of the size, length, shape, and number of bytes the array requires.

numpy Tags:array, length, nbytes, shape, size

Post navigation

Previous Post: What are the max and min values of integer in Python?
Next Post: How to add a list to a set in Python?

Categories

  • bokeh (1)
  • datetime (3)
  • Django (5)
  • glob (1)
  • io (1)
  • json (1)
  • math (5)
  • matplotlib (10)
  • numpy (95)
  • OpenCV (1)
  • os (3)
  • Pandas (2)
  • paramiko (1)
  • pathlib (2)
  • Pillow (3)
  • Plotly (3)
  • Python (29)
  • random (7)
  • requests (1)
  • Scipy (4)
  • Seaborn (7)
  • shutil (1)
  • sqlite3 (1)
  • statistics (16)
  • sys (1)
  • Tkinter (9)
  • turtle (2)
  • Uncategorized (1)
  • urllib (1)
  • webbrowser (1)

RSS RSS

  • How to create violin plot using seaborn?
  • How To Use Colormaps In Matplotlib?
  • How to calculate bonds in Python
  • How to handle trigonometry in Python
  • How to Convert Int to Binary in Python?
  • How to fix ValueError: The truth value of an array with zero elements is ambiguous?
  • How to solve NameError: name ‘numpy’ is not defined
  • How to insert seaborn lineplot?
  • How to Find the Length of an Array in Python?
  • How to reset secret key in Django

Tags

arithmetic mean array axis button calculations chart conversion copy count counter data type dictionary dimension draw error files fill float generate grid GUI image index integer list matrix max mean median min normal distribution plot random reshape rotate round size standard deviation string sum test text time variance zero

Copyright © 2023 Pythoneo.

Powered by PressBook WordPress theme

We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept”, you consent to the use of ALL the cookies.
Cookie settingsACCEPT
Manage consent

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Non-necessary
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
SAVE & ACCEPT