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

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!