File Handling in Python: Reading and Writing

Real-world programs often need to work with files. Python makes file handling straightforward. You use the open() function, which takes a filename and a mode. The mode can be 'r' for reading, 'w' for writing, 'a' for appending, or 'r+' for both reading and writing. It is good practice to use a with statement because it automatically closes the file after you are done. For reading a file, you can do with open('file.txt', 'r') as file: content = file.read(). This reads the entire file into a string. If the file is large, you might want to read line by line using a loop. For writing, use 'w' mode. Be careful: this will overwrite the file if it exists. If you want to add to the end, use 'a' mode. You can write with file.write("your text"). File handling is essential for many tasks like logging, data storage, and configuration. A common beginner project is to create a simple note-taking application. The program could let the user write notes, save them to a file, and later read them back. This teaches you how to persist data between program runs. Remember to handle exceptions like FileNotFoundError to make your programs robust.