Reading, Writing, and Manipulating Files in Python

Python provides several built-in functions and methods for reading, writing, and manipulating files. This article will cover these functions and methods in detail.

Understanding File Objects

In Python, a file is treated as an object. The built-in open() function is used to create a file object which provides a connection to the file that resides on your machine.

file = open('example.txt', 'r')

In the above example, 'example.txt' is the name of the file and 'r' is the mode which stands for read. There are several modes you can specify when opening a file:

• 'r': read mode
• 'w': write mode
• 'a': append mode
• 'b': binary mode
• '+': read and write mode

Opening and Closing Files

Once a file is opened and you have done your operations on the file, it is always a good practice to close the file. This is done using the close() method.

file.close()

Reading from Files

Python provides several methods to read from a file:

• read(): This method reads the entire content of the file.
• readline(): This method reads the next line of the file.
• readlines(): This method reads all the lines of the file and returns them as a list.

Writing to Files

To write to a file, you need to open it in write 'w', append 'a', or exclusive creation 'x' mode.

• write(): This method writes a string to the file.
• writelines(): This method writes a list of strings to the file.

File Positions

• tell(): This method returns the current position of the file read/write pointer within the file.
• seek(offset[, from]): This method changes the current file position. The offset argument indicates the number of bytes to be moved. The from argument specifies the reference position from where the bytes are to be moved.

Working with CSV and JSON Files

Python provides the csv and json modules to read and write to CSV and JSON files.

File Manipulation: Renaming and Deleting Files

The os module in Python provides functions for creating, renaming, and deleting files.

• rename(): This method takes two arguments, the current filename and the new filename.
• remove(): This method deletes the file.

In conclusion, Python provides a rich set of tools to work with files. It is important to understand these tools to effectively work with data stored in files.