To a computer user, a file is a named set of information that is useful for a particular purpose. This could be a document, a picture, a song, or any other type of data. The filename itself may not be critically important, as long as the file is accessible and can retain the data over time, typically stored on long-term storage devices like hard disk drives.

For your programs, files are just as useful but require a bit more management to ensure that they work correctly.

File handling is an essential part of programming, enabling the reading, writing, and manipulation of files. In Python, the primary function used for file handling is open().

• The open() Function

The open() function takes two parameters:

• Filename: The name of the file you want to open.
• Mode: Specifies the purpose of opening the file.

File Modes

Here are the different modes for opening a file:

• Read Mode ("r"):

• Opens a file for reading.
• Returns an error if the file does not exist.
• Default mode.

f = open("demofile.txt", "r")

• Append Mode ("a"):

• Opens a file for appending (adding content to the end).
• Returns an error if the file does not exist.

f = open("demofile.txt", "a")

• Write Mode ("w"):

• Opens a file for writing.
• Creates the file if it does not exist.
• Overwrites the file if it exists.

f = open("demofile.txt", "w")

• Create Mode ("x"):

• Creates the specified file.
• Returns an error if the file exists.

f = open("demofile.txt", "x")

Text and Binary Modes

In addition to the basic modes, you can specify how the file should be handled:

• Text Mode ("t"):

• Default mode.
• Opens the file in text mode.

• Binary Mode ("b"):
  • Opens the file in binary mode.
  • Useful for non-text files (e.g., images, executable files).