Book Image

Python Essentials

By : Steven F. Lott
Book Image

Python Essentials

By: Steven F. Lott

Overview of this book

Table of Contents (22 chapters)
Python Essentials
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

The essential file concept


Modern OSs rely on files and device drivers for a variety of services and features. Bytes on a disk drive are only one type of file.

Note

Since many storage devices use or include Solid State Drives (SSD) the term "disk" is technically a misnomer; we'll use the outdated term.

A network adapter is another kind of file; one in which bytes are available continuously, instead of appearing at rest. In addition to disk and network files, the Linux filesystem includes the /dev directory, which describes all of the devices on a given computer. These devices include serial ports, references to memory, and even a device which accumulates an entropy pool to provide random bytes.

The Python file object wraps an OS file. The open() function binds a Python file object to an OS file. In addition to a name, the function expects a mode string for access. The mode string combines two features:

  • Characters versus bytes: By default, a file is opened in text mode; we can make this explicit...