File Handling Basics

File handling in programming allows you to create, read, update, and delete files on your computer.
Files can hold various types of data such as text, images, audios, videos, etc.
File handling is necessary when you want to store data permanently or exchange data between different programs.
Most programming languages provide built-in support for file handling.

Opening and Closing Files

Before reading from or writing to a file, you must first open the file.
You can open a file in different modes, such as read mode (r), write mode (w), and append mode (a).
In write mode, if the file does not exist, it will be created. If it does exist, the existing content will be deleted before the new write operation.
In append mode, new data will be added at the end of the file, not erasing the existing data.
Once you’re done with a file, you should close it. This frees up the resources that were tied with the file and is done using the close() function.

When a file is opened in read mode, you can use the read() function to read the file’s content.
Often, files are read line by line using a loop and the function readline().
Always ensure that the file exists before attempting to open and read it. Otherwise, the program might crash.

When a file is opened in write or append mode, you can write data to the file using the write() function.
Using a loop, you can write multiple lines of data to a file.
Remember, in write mode, the existing content of the file is deleted before new data is written.

When opening a file, you need to provide the file path, which tells your program where the file is located on your computer.
A relative file path specifies the file’s location in relation to the current folder, while an absolute file path specifies the file’s exact location on the computer.

It’s important to use error handling techniques when performing file operations to prevent your program from crashing if something unexpected happens (like trying to open a file that doesn’t exist).
For example, a try/except block can be used to catch and handle exceptions that are raised when attempting to perform file operations.

When working with text, you usually open the file in text mode (t), but for non-text files like images or executables, you open the file in binary mode (b).
Binary mode doesn’t translate the file in any way and the contents are read and written as they are.