How to Create Full Array in NumPy: Simple Guide

To create a full array in NumPy, use the numpy.full(shape, fill_value) function, where shape defines the array size and fill_value is the value to fill. This creates an array of the given shape filled entirely with the specified value.

Syntax

The basic syntax to create a full array in NumPy is:

• numpy.full(shape, fill_value, dtype=None, order='C')

shape: tuple or int defining the array dimensions.
fill_value: the value to fill the array with.
dtype (optional): data type of the array.
order (optional): memory layout, 'C' for row-major (default) or 'F' for column-major.

python

numpy.full(shape, fill_value, dtype=None, order='C')

Example

This example creates a 3x3 array filled with the number 7. It shows how to specify the shape and fill value.

python

import numpy as np

full_array = np.full((3, 3), 7)
print(full_array)

Output

[[7 7 7]
 [7 7 7]
 [7 7 7]]

Common Pitfalls

Common mistakes include:

• Passing a single integer instead of a tuple for shape when creating multi-dimensional arrays.
• Forgetting to import NumPy before using full().
• Using fill_value incompatible with the default data type, which can cause unexpected results.

python

import numpy as np

# Wrong: shape as int for 2D array
# full_array_wrong = np.full(3, 7)  # creates 1D array, not 2D

# Right: shape as tuple for 2D array
full_array_right = np.full((3, 3), 7)
print(full_array_right)

Output

[[7 7 7]
 [7 7 7]
 [7 7 7]]

Quick Reference

Remember these tips when using numpy.full():

• Use a tuple for shape to create multi-dimensional arrays.
• Specify dtype if you want a specific data type.
• Use order='F' for column-major order if needed.

Key Takeaways

Use numpy.full(shape, fill_value) to create an array filled with a specific value.

Always pass shape as a tuple for multi-dimensional arrays.

Specify dtype to control the data type of the array elements.

Remember to import numpy before using its functions.

Check the fill_value compatibility with the array's data type.