How to Print a List in Matrix Form in Python

This tutorial is designed to guide you through the process of printing a list in matrix form using Python.

The Python programming language offers a variety of methods for representing data, and one common format is the matrix. A matrix is a 2-D data structure where numbers are arranged into rows and columns – it’s particularly handy in mathematical and scientific calculations.

Step 1: Define Your Matrix

The first step in printing a list as a matrix is to define the matrix. In Python, we can create a matrix using nested lists, where each inner list represents a row of the matrix. For simplicity, let’s consider a 2×2 matrix.

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matrix = [[1, 2], [3, 4]]

Step 2: Use nested for Loop

Now that we have our matrix defined, we can print it in the form of a matrix within the terminal using a nested for loop.

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for row in matrix:
    for num in row:
        print(num, end=" ")
    print()

Output:

1 2
3 4

Step 3: Use List Comprehension

Alternatively, we can use list comprehension, a compact way of creating lists. Here is how to do it:

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print('\n'.join([' '.join([str(num) for num in row]) for row in matrix]))

Output:

1 2
3 4

Step 4: Using NumPy

The NumPy library is a powerful way for representing matrices and includes features for performing a vast array of mathematical operations. If we have the NumPy, we can use it to print a list as a matrix.

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import numpy as np
np_matrix = np.array(matrix)
print(np_matrix)

Output:

[[1 2]
 [3 4]]

Full Code

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matrix = [[1, 2], [3, 4]]
 
# Using nested for loop
for row in matrix:
    for num in row:
        print(num, end=" ")
    print()
 
# Using list comprehension
print('\n'.join([' '.join([str(num) for num in row]) for row in matrix]))
 
# Using NumPy
import numpy as np
np_matrix = np.array(matrix)
print(np_matrix)

Output

1 2 
3 4 
1 2
3 4
[[1 2]
 [3 4]]

Conclusion

There we have it! We just learned how to print a list in the form of a matrix using Python. The context and specifics will dictate which method to use, but these three methods provide a robust range of options to suit your needs. The nested loop allows for simple representation, list comprehension offers a concise alternative, and NumPy is the most versatile, especially for mathematical operations. Happy coding!