How To Write A Multidimensional Array To A Text File?

In this article, we will explain how to write a multidimensional array to a text file with the help of a few examples. Writing a multidimensional array to a text file is a straightforward process, and it allows you to print the array directly to the text file in a simple manner.

Write A Multidimensional Array To A Text File

To write a multidimensional array to a text file in Python, follow the steps below

Create a Virtual Environment

Create the virtual environment using the below command.

python -m venv env
.\env\Scripts\activate.ps1

Create an Output File

Create a Text file in the same folder for printing the Multidimensional Array.

File Structure

Code Example

Example 1: Write Two Dimensional Array To A Text File

In this example, below code creates a 2D array named two_d_array, converts it to a formatted string (array_string) with rows separated by newline and elements within each row separated by a tab, then writes the string to a file named ‘output.txt’. Finally, it prints the original 2D array and a message indicating that the output has been written to ‘output.txt’.

Python3

# Example 2D Array
two_d_array = [
    [1, 2, 3],
    [4, 5, 6],
    [7, 8, 9]
]

# Convert 2D Array to String
array_string = '\n'.join(['\t'.join(map(str, row)) for row in two_d_array])

# Write to File
with open('output.txt', 'w') as file:
    file.write(array_string)

# Display Output
print("2D Array:")
for row in two_d_array:
    print(row)

print("\nOutput Written to output.txt")

Output :

1, 2, 3
4, 5, 6
7, 8, 9

Example 2: Write Three Dimensional Array To A Text File

In this example, below Python code defines a three-dimensional array with dimensions 2x3x4, initializes it with sequential values, and then writes the array to an “output.txt” file. The array is created using nested list comprehensions, filled with values incrementally, and each element is written to the file with space separation. Two additional lines of code are suggested to add a newline after each row and a blank line after each second dimension in the file.

Python3

# Define the dimensions of the array
first_dimension = 2
second_dimension = 3
third_dimension = 4

# Initialize the three-dimensional array with zeros
three_dimensional_array = [[[0 for _ in range(third_dimension)]
                            for _ in range(second_dimension)]
                           for _ in range(first_dimension)]

# Fill the array with values
value = 1
for i in range(first_dimension):
    for j in range(second_dimension):
        for k in range(third_dimension):
            three_dimensional_array[i][j][k] = value
            value += 1

# Open a file for writing
with open("output.txt", "w") as file:
    # Write the three-dimensional array to the file
    for i in range(first_dimension):
        for j in range(second_dimension):
            for k in range(third_dimension):
                file.write(f"{three_dimensional_array[i][j][k]} ")
            file.write("\n")
        file.write("\n")

# Print a message
print("\nOutput Written to output.txt")

Output :

1 2 3 4 
5 6 7 8 
9 10 11 12 

13 14 15 16 
17 18 19 20 
21 22 23 24 

Conclusion

In Python, the process of writing a multidimensional array to a text file involves initially converting the array into a string representation and subsequently saving it using file handling functions. This tutorial covers fundamental concepts of arrays, file management, and the necessary steps to accomplish this task. We demonstrated this process with a basic 2D list, converting it into a string and writing the result to a file to exemplify handling a 2D array