WRITE FILES using Python! (.txt, .json, .csv) ✍

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Published on Mar 15, 2025 This response is partially generated with the help of AI. It may contain inaccuracies.

Table of Contents

Introduction

In this tutorial, we will learn how to write data to different file formats using Python, specifically .txt, .json, and .csv files. This is a fundamental skill for data handling and storage in programming, making it essential for anyone looking to work with data in Python.

Step 1: Writing to a .txt File

To start, we will write data to a plain text file.

  1. Open a file in write mode:

    • Use the open() function with the mode set to "w".
    with open('example.txt', 'w') as file:
        file.write("Hello, this is a text file.")
    
    • This code creates a file named example.txt and writes a string to it.
  2. Using absolute file paths:

    • If you want to specify a location, use an absolute path.
    with open('/path/to/your/directory/example.txt', 'w') as file:
        file.write("This is an absolute path example.")
    
    • Replace /path/to/your/directory/ with the actual path on your system.
  3. Understanding file modes:

    • "w" mode will overwrite any existing file.
    • To create a new file without overwriting, use "x" mode:
    with open('newfile.txt', 'x') as file:
        file.write("This file was created with mode 'x'.")
    

Step 2: Appending to a .txt File

If you want to add content to an existing file without erasing it, use "a" mode.

  1. Open a file in append mode:
    with open('example.txt', 'a') as file:
        file.write("\nAdding another line to the text file.")
    
    • This adds a new line to example.txt without deleting previous content.

Step 3: Writing to a .json File

Next, we will write data to a JSON file, which is useful for structured data.

  1. Import the json module:

    import json
    
  2. Prepare your data:

    • Use a Python dictionary or list to organize your data.
    data = {
        "name": "John",
        "age": 30,
        "city": "New York"
    }
    
  3. Write to a JSON file:

    with open('data.json', 'w') as json_file:
        json.dump(data, json_file, indent=4)
    
    • This creates data.json with a structured format.

Step 4: Writing to a .csv File

Finally, we will write data to a CSV file, which is commonly used for tabular data.

  1. Import the csv module:

    import csv
    
  2. Prepare your data:

    • Organize your data as a list of dictionaries or a list of lists.
    data = [
        ["name", "age", "city"],
        ["Alice", 25, "Los Angeles"],
        ["Bob", 30, "Chicago"]
    ]
    
  3. Write to a CSV file:

    with open('data.csv', 'w', newline='') as csv_file:
        writer = csv.writer(csv_file)
        writer.writerows(data)
    
    • This creates data.csv with the specified content.

Conclusion

In this tutorial, we covered how to write to .txt, .json, and .csv files using Python. Key points include:

  • Use appropriate modes ("w", "a", "x") when opening files.
  • Understand the structure of JSON and CSV files for effective data storage.
  • Utilize the json and csv modules for handling specific file formats.

Next, you can explore reading from these files or handling exceptions for more robust programming practices. Happy coding!