Print Full Numpy Array without Truncation

NumPy is a powerful Python library for handling large, multi-dimensional arrays. However, when printing large NumPy arrays, the interpreter often truncates the output to save space and shows only a few elements with ellipsis (...). In this article, we will explore how to print a full NumPy array without truncation.

Understanding the Problem

To understand the truncation issue, consider this example:

import numpy as np

# Create a large array with 1100 elements
array = np.arange(1100)
print(array)

[   0    1    2 ... 1097 1098 1099]

In the above example, we created an array with 1100 elements. The Python interpreter automatically truncates it and uses triple dots (...) to indicate that some elements are not displayed.

Method 1: Using set_printoptions()

The set_printoptions() method allows us to modify how arrays are displayed when printed. To print the whole array, we set the threshold parameter to np.inf.

Example 1: Random Array

import numpy as np

# Generate a random NumPy array
array = np.random.rand(5, 3)

# Set print options to display entire array
np.set_printoptions(threshold=np.inf)

# Print the generated array
print(array)

[[0.37454012 0.95071431 0.73199394]
 [0.59865848 0.15601864 0.15599452]
 [0.05808361 0.86617615 0.60111501]
 [0.70807258 0.02058449 0.96990985]
 [0.83244264 0.21233911 0.18182497]]

Example 2: Large Sequential Array

import numpy as np

# Create a NumPy array with 40 consecutive values
array = np.arange(40)

# Set print options to display entire array
np.set_printoptions(threshold=np.inf)

# Display the result
print(array)

[ 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39]

Example 3: Using sys.maxsize

import numpy as np
import sys

# Generate a random NumPy array
array = np.random.rand(5, 3)

# Set print options using sys.maxsize
np.set_printoptions(threshold=sys.maxsize)

# Display the result
print(array)

[[0.77395605 0.43887844 0.85859792]
 [0.69736803 0.09417735 0.97562235]
 [0.7611397  0.78606431 0.12811363]
 [0.45038594 0.37079802 0.92676499]
 [0.64386512 0.82276161 0.4434142 ]]

Method 2: Using array2string()

The array2string() method converts an array into a string representation. To print the whole array, we pass the array as a parameter and set the threshold parameter to np.inf.

Example

import numpy as np

# Generate a random NumPy array
array = np.random.rand(5, 5)

# Convert the array to a string without truncation
array_string = np.array2string(array, threshold=np.inf)

# Print the converted array string
print(array_string)

[[0.891773   0.96366276 0.38344152 0.79172504 0.52889492]
 [0.56804456 0.92559664 0.07103606 0.0871293  0.0202184 ]
 [0.83261985 0.77815675 0.87001215 0.97861834 0.79915856]
 [0.46147936 0.78052918 0.11827443 0.63992102 0.14335329]
 [0.94466892 0.52184832 0.41466194 0.26455561 0.77423369]]

Comparison

Resetting Print Options

To reset print options back to default after using set_printoptions():

import numpy as np

# Reset to default print options
np.set_printoptions(threshold=1000)  # Default threshold

Conclusion

Use set_printoptions(threshold=np.inf) for global array printing configuration or array2string(threshold=np.inf) for individual array string conversion. Both methods effectively prevent NumPy array truncation and display complete arrays regardless of size.