Data Files in Python

In Python, a data file is a file that stores data. The data can be in many forms, such as text, binary, json, csv, etc. Python provides built-in functions to read from and write to data files.

1. Text Files

These are the most common file that you’ll come across. They can be opened in a standard text editor. Here’s an example of how you can write to a text file:

# Writing to a file
with open('myfile.txt', 'w') as f:
    f.write('Hello, world!')

And reading from a text file:

# Reading from a file
with open('myfile.txt', 'r') as f:
    content = f.read()
    print(content)  # Output: Hello, world!

2. Binary Files

These are files that are not in a human-readable format. Here’s an example of writing binary data to a file:

# Writing binary data to a file
with open('myfile.bin', 'wb') as f:
    f.write(b'\x3c\x2f\x66\x6f\x6f\x3e')  # Writes '' in ASCII

And reading from a binary file:

# Reading binary data from a file
with open('myfile.bin', 'rb') as f:
    content = f.read()
    print(content)  # Output: b''

3. CSV (Comma-Separated Values) Files

These are a type of flat file which uses specific structuring to arrange tabular data. Python provides a csv module to deal with CSV files. Here’s an example of writing to a CSV file:

import csv
# Writing to a CSV file
with open('myfile.csv', 'w', newline='') as f:
    writer = csv.writer(f)
    writer.writerow(["SN", "Name", "Contribution"])
    writer.writerow([1, "Linus Torvalds", "Linux Kernel"])
    writer.writerow([2, "Tim Berners-Lee", "World Wide Web"])

And reading from a CSV file:

import csv
# Reading from a CSV file
with open('myfile.csv', 'r') as f:
    reader = csv.reader(f)
    for row in reader:
        print(row)

4. JSON (JavaScript Object Notation) Files

These are a popular data exchange format and are human readable. The json module in Python provides a method called json.dump() for writing data to JSON files. Similarly, we can use json.load() to read data from a JSON file.

import json
# Writing to a JSON file
data = {
    "Name": "Zophie",
    "Species": "cat",
    "age": 7
}
with open('data.json', 'w') as f:
    json.dump(data, f)

And reading from a JSON file:

import json
# Reading from a JSON file
with open('data.json', 'r') as f:
    data = json.load(f)
    print(data)  # Output: {'Name': 'Zophie', 'Species': 'cat', 'age': 7}

Please remember to replace ‘myfile.txt’, ‘myfile.bin’, ‘myfile.csv’, and ‘data.json’ with the path to your own file. If you don’t provide a full path, Python will look for the file in the same directory as the script you’re running.