How to Print a Column of a Matrix in Python?

Python is one of the most versatile and widely used programming languages today. In this tutorial, we are going to focus on Python’s capabilities when dealing with matrices.

Indeed, data analysis often demands complex manipulations of matrices and Python is well-equipped to handle these tasks. Here, we will specifically look at how to print a column of a matrix in Python.

Step 1: Creating a Matrix

The first step is to create a matrix. Python doesn’t have a built-in type for matrices. However, we can treat a list of a list as a matrix. For example, here is a matrix with 3 rows and 3 columns:

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matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

Step 2: Accessing a Column in a Matrix

To access or print a column of a matrix in Python you need to use a loop or list comprehension. Let’s print the first column of the matrix (index 0):

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column = [row[0] for row in matrix]
print(column)

Step 3: Generalizing to any Column

If you want to print any other column, just replace the column index within the square brackets in row[0] accordingly. This method works because we’re iterating over each row in the matrix, and then grabbing the first item of each row. Here’s a generalized function:

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def print_column(matrix, column_number):
    column = [row[column_number] for row in matrix]
    print(column)

Step 4: Putting it all Together

Now, by calling the function print_column and specifying the matrix and the column number, you can print any column of a matrix. Let’s use our previous matrix and print the third column:

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print_column(matrix, 2)

Full Code

As promised, here is the full code:

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matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
 
def print_column(matrix, column_number):
    column = [row[column_number] for row in matrix]
    print(column)
 
print_column(matrix, 2)

Output

[3, 6, 9]

Conclusion

With Python, manipulating and printing columns of a matrix is simplified down to a few lines of code. This makes the language an excellent option for data analysis and matrix manipulation.

With further exploration, you will find Python to have more capabilities that will make your data analysis tasks easier, quicker, and more enjoyable.