Opening and closing a file in Python using file I/O

In order to gain access to a file, a computer program needs to interact with the operating system; the process is called file I/O. File I/O is the way in which a programming language is able to open, read from, write to, and close files. (The I/O here stands for input/output, because the program takes input from certain files and writes output to other files.)

Note

While it is not always necessary to explicitly open a file, it is important to conceptually separate the process of opening a file from the process of reading the contents of a file. This is because it is often necessary to read the contents of a file incrementally or specify particular parameters when the file is opened.

In the following subsection, I will show to use python to open a file.

The open function and file objects

To open a file, you can use Python's built-in open() function:

file = open("<relative/path/to/file>", "<permission>")

The variable named file in the...