17. File Handling

Quiz: 0/5

Imagine storing information like your favorite recipes, a journal, or even game scores in a file. Python makes it simple to work with files so you can save data for later use or read data from existing files.

Opening and closing files in Python

To work with a file, you need to open it first. Python provides the open() function to do this.

Example:

file = open("example.txt", "r")  # Opens a file in read mode
file.close()  # Always close a file after using it

Modes for opening files:

• r: Read (default)
• w: Write (overwrites the file or creates it if it doesn't exist)
• a: Append (adds to the file without overwriting)

Reading from a file

You can read the contents of a file using the read() method.

Example:

file = open("example.txt", "r")
content = file.read()
print(content)  # Displays the content of the file
file.close()

Writing to a file

To add text to a file, use the write() method. Be careful: writing will erase the file's previous content.

Example:

file = open("example.txt", "w")
file.write("Hello, Python!")  # Writes text to the file
file.close()

Safely handling files with with

Using with ensures the file is closed automatically, even if something goes wrong.

Example:

with open("example.txt", "r") as file:
    content = file.read()
    print(content)  # The file is automatically closed after this block

Key takeaways

• Always close your files or use the with statement.
• Use the correct file mode (r, w, a) depending on your task.
• Reading and writing files is simple but powerful for real-world applications.