Numpy – Print Array With Commas

The Numpy library in Python comes with a number of useful functions to work with and manipulate arrays. In this tutorial, we will look at how to print a numpy array with elements separated by commas with the help of some examples.

Printing a Numpy Array

First, let’s see what we get when we directly print a numpy array.

import numpy as np

# create numpy array
ar = np.array([1, 2, 3, 4, 5])
# print the array
print(ar)

Output:

[1 2 3 4 5]

Here, we created a numpy array of five numbers and then printed it using the print() function. You can see that the elements are printed with a space between them.

How to print a numpy array with commas?

You can use the numpy array2string() function to print a numpy array with elements separated by commas. Pass the array and the separator you want to use (“,” in our case) to the array2string() function.

The following is the syntax –

# print numpy array with "," separator
print(np.array2string(ar, separator=","))

It returns a string representation of the array with the given separator.

Let’s now apply this function to the above array such that its elements are separated by commas on printing.

# print array with "," as separator
print(np.array2string(ar, separator=","))

Output:

[1,2,3,4,5]

The array elements are separated by commas.

If the printed array looks cluttered, you can specify , (a comma followed by a space) as the separator.

# print array with ", " as separator
print(np.array2string(ar, separator=", "))

Output:

[1, 2, 3, 4, 5]

The elements now look less cluttered.

Use the repr() function

Alternatively, you can use the Python built-in repr() function to print a numpy array with commas. The repr() function is used to print the string representation of an object in Python.

Let’s look at an example.

print(repr(ar))

Output:

array([1, 2, 3, 4, 5])

The array elements are separated by commas. Note that the output is not exactly the same as what we got with the array2string() function.

Summary – Print Numpy Array with Comma as a Separator

In this tutorial, we looked at how to print a numpy array with a comma as a separator. The following are the steps mentioned in this tutorial –

• Create a numpy array (skip this step if you already have a numpy array to operate on).
• Use the numpy array2string() function to get a string representation of the array with the desired separator (a comma in our case).
  There are alternative methods as well, such as using the repr() function.

You might also be interested in –

• Remove Last Element From Numpy Array
• Find Index of Element in Numpy Array